00 ITSB Foundation

8/3/2019 00 ITSB Foundation

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An Introduction

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IT Systems In Business


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System

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A set of elements or components that interact toaccomplish goals

Components of the systems Input

Processing mechanism

Output

Feedback


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Systems Classification

3


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Modeling a System

4

A model is an abstraction that is used torepresent reality

4 major types of models A narrative model is based on words

Logical, not physical A physical model is tangible

A schematic model is a graphic representation

Graphs and charts

A mathematical model is an arithmetic representation


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Modeling a System

5


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Information System

6

It is a set of interrelated components that collect,manipulate, and disseminate data andinformation, and provide feedback to meet anobjective

Examples: ATMs, airline reservation systems,Railway reservation systems


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7

What is an Information System?

Input ofDataResources

ProcessingData

Output ofInformationProducts

Control of System Performance

Storage of Data Resources


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Data Vs. Information

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Data: raw facts

Information: collection of facts organized in such

a way that they have value beyond the factsthemselves


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Data Vs. Information

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10

Data versus Information

Monthly Sales Reportfor West Region

Sales Rep: Charles MannEmp No. 79154Item Qty Sold PriceTM Shoes 1200 $100


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Turning Data Into Information

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Turning data into information is a process or setof related tasks performed to achieve a definiteoutcome

Data

Transformation

of data into

information

by applying

knowledge toselect, organize

and manipulate

data

Information


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Types of Data

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Alphanumeric data - Numbers, letters and othercharacters

Images - Graphic Images, pictures

Audio - Sound files

Video - Moving video files, clips


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Attributes of Information Quality

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Accurate Complete

Economical

Flexible

Reliable Relevant

Simple to use

Timely

Verifiable Accessible

Secure


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Attributes of Information Quality

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Components of an InformationSystem

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Input Processing Output

Feedback


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Information System Activities

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Input of data resources Processing of data into information

Output of Information

Storage of data Control of System performance


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Examples of IS in Business Functions using IS

Finance and Accounting

Sales and Marketing

Manufacturing

Companies using IS Investment firms

Banks

Publishing companies

Healthcare organizations

Management consulting firms

Telecommunication and..

Btw.. Tell me who is not using it ?

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Components of an InformationSystem


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Components of a CBIS

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Components of a CBIS

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People Processes

Technology

Hardware Software

Data

Network

Internet


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But.. Why do we need IS Lowe costs Differentiate

Innovate

Promote growth Develop alliances

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Major Roles of InformationSystems

Support ofStrategic

Advantage

Support ofManagerial

Decision Making

Support ofBusiness Operations


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23

History of the role of InformationSystems

DataProcessing

ManagementReporting

DecisionSupport

Strategic &End User

ElectronicCommerce

1950-1960 1960-1970 1970-1980 1980-1990 1990-2000

ElectronicDataProcessing- TPS

ManagementInformationSystems

DecisionSupportSystems- Ad hoc

Reports

End UserComputingExec Info Sys

Expert SystemsSIS

ElectronicBusiness &Commerce-InternetworkedE-Business &Commerce


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What is expected of you ? As a business professional,

You should be able to recognize the fundamentalcomponents of IS in the real world

The people, hardware, software, data and networkcomponents of the IS

The type of data required and information produced bythe system

The way the IS perform the input, processing, output,storage and control activities

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Hardware


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Hardware is .

that part of computerwhich

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you can actually kick


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Worlds First Computer

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(1387 AD)


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Computer System Categories

MainframeComputers

MidrangeComputers

Microcomputers


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Microcomputer Systems

Handheld Computers PDA, Information

Appliances

Notebook Computers Desktop Computers

Workstations


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Network Computers and Terminals

Network Computer(Thin Client)

NetPC

Network Terminal

Benefits Lower purchase cost

Easier maintenance

Easier software

distribution andlicensing

Computer platformstandardization

Reduced end usersupport requirements

Improved manageability


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Client Server Networking

ClientSystems

Servers

Host Systems/Superservers


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Hardware Components

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Central processing unit (CPU) Primary storage (main memory)

Secondary storage

Motherboard Others

Input devices

Output devices


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Computer System Components

Central Processing Unit

Output

Devices

CacheMemory

PrimaryStorage

SecondaryStorageDevices

ControlUnit

ALU

SpecialPurposeProcessors

Output

DevicesInput

Devices

KeyboardMouseTouch Screen

Optical ScannerVoice Recognition

Visual Display UnitPrinterAudio-Response

Physical Control Devices

Magnetic tapesTape Units

Optical discs


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Central Processing Unit

The microprocessor"brain" of the computersystem

Everything that acomputer does isoverseen by the CPU

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Hardware Components in Action

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Step 1: Fetch instruction Step 2: Decode instruction

Step 3: Execute the instruction

Step 4: Store results


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Hardware Components in Action

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Trends in Computer SystemCapabilities

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FirstGeneration

SecondGeneration

ThirdGeneration

FourthGeneration

FifthGeneration

VacuumTubes

Solid-StateIntegrated

Circuits

LSI, VLSIMicro-

processors

GreaterPower,Smaller

Footprint

Trend:Toward Smaller, Faster, More Reliable, and Less Costly

Trend:Toward Easy to Purchase, and Easy to Maintain


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Primary Storage Media

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Storage used to hold data

Some memory connect directly to the microprocessor

Random-access memory (RAM) - Used to temporarily store information that thecomputer is currently working with

Read-only memory (ROM) - A permanent type of memory storage used by thecomputer for important data that does not change

Basic input/output system (BIOS) - A type of ROM that is used by the computer toestablish basic communication when the computer is first turned on

Caching - The storing of frequently used data in extremely fast RAM that connectsdirectly to the CPU

Virtual memory - Space on a hard disk used to temporarily store data and swap it inand out of RAM as needed


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Cache Memory

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Secondary Storage Media

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Some memory use for permanent storage

Hard disk - large-capacity permanent storage used to hold information such asprograms and documents

Removable storage - devices that allow to add new information to your computervery easily, as well as save information that you want to carry to a different

location

Floppy disk - inexpensive and easy to save information to Now almost obsolete

CD-ROM (compact disc, read-only memory) - popular form of distribution ofcommercial software. CD-R (recordable) and CD-RW (rewritable)

Flash memory - Based on a type of ROM called electrically erasable programmableread-only memory (EEPROM), Flash memory provides fast, permanent storage

DVD-ROM - DVD-ROM (digital versatile disc, read-only memory) - similar to CD-ROM but capable of holding much more information.


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Secondary Storage

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Advantages Non-volatility

greater capacity

greater economy

Access methods, storage capacities, and portabilityrequired are determined by the information systems

objectives


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Access Methods

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Sequential: records must be retrieved in order Devices used are called sequential access storage

devices (SASD)

Direct: records can be retrieved in any order

Devices used are called direct access storagedevices (DASDs)


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Devices

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Magnetic tapes Magnetic disks

RAID

Storage area networks (SAN) Optical disks

Digital versatile disks (DVDs)


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Magnetic Disks

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Characteristics of Magnetic Disks

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Cylinders

AccessMechanism

AccessArms

Read/WriteHeads

Disks

Tracks: Concentric circlesfor storing data as magnetizedbits.

Sectors:Portions of a track

Track


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Primary & Secondary Storage Media

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Semiconductor

Memory

MagneticDisks

Floppy DiskHard Disk, RAID

Magnetic Tape

Optical DisksCD-ROM, CD-R

CD-RWDVD

Direct

Access

Sequential

Access

Direct

Access


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Storage Trends

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FirstGeneration

SecondGeneration

ThirdGeneration

FourthGeneration

FifthGeneration

MagneticDrum

MagneticCore

MagneticCore

LSISemiconductor

Memory Chips

VLSISemiconductor

Memory Chips

Trend:Towards Large Capacities Using Smaller Microelectronic Circuits

Trend:Towards Massive Capacities Using Magnetic and Optical Media

Magnetic TapeMagnetic Drum Magnetic TapeMagnetic Disk Magnetic DiskMagnetic Tape

Magnetic Disk

Optical DiskMagnetic Tape

Optical DiskMagnetic Disk

Primary

Storage

SecondaryStorage


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Motherboard

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Main circuit board that all of the other internalcomponents connect to

The CPU and memory are usually on the

motherboard

Other systems may be found directly on themotherboard or connected to it through a secondary

connection For example, a sound card can be built into the motherboard

or connected through PCI.


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Other parts of the Computer

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Integrated Drive Electronics (IDE) Controller primary interface for the hard drive, CD-ROM and floppy disk

drive

AGP (Accelerated Graphics Port)

Very high-speed connection used by the graphics card to

interface with the computer

Sound card

Used by the computer to record and play audio by convertinganalog sound into digital information and back again

Graphics card translates image data from the computer into a format that can

be displayed by the monitor.


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Input Devices

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Personal computer input devices Keyboard

Mouse

Voice-recognition devices

Digital cameras Scanners

Touch sensitive screens

Bar code scanners

Speech Recognition Magnetic Ink Character Recognition

Smart Cards


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Input Technology Trends

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FirstGeneration

SecondGeneration

ThirdGeneration

FourthGeneration

FifthGeneration

PunchedCards

Paper Tape

PunchedCards

Key to Tape/Disk

Keyboard Data EntryPointing DevicesOptical Scanning

Voice RecognitionSpeech andTouch DevicesHandwritingRecognition

Trend:Towards Direct Input Devices that Are More Naturaland Easy to Use


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Common Output Devices

Video Output

CRT

LCD

Printed Output Inkjet

Laser

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Output Technology Trends

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FirstGeneration

SecondGeneration

ThirdGeneration

FourthGeneration

FifthGeneration

PunchedCardsPrinted Reportsand Documents

PunchedCardsPrinted Reportsand Documents

Printed Reportsand DocumentsVideo Displays

Video DisplaysAudio ResponsesPrinted Reportsand Documents

Video Displays

Voice ResponsesHyperlinkedMultimediaDocuments

Trend:Towards Output Methods that Communicate Naturally,Quickly, and Clearly


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Systems and Application Software

Software

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Software is

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that part of computerwhich

You can only curse


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An Overview of Software

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Computer program - sequences of instructions forthe computer

Types of Software

Systems software - coordinates the activities ofhardware & programs

Applications software - helps users solve particularproblems


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Categories of Computer Software

General-Purpose

Programs

Application-Specific

Programs

SystemManagement

Programs

SystemDevelopment

Programs

ApplicationSoftware

ComputerSoftware

SystemSoftware


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Trends in Computer Software

FirstGeneration

SecondGeneration

ThirdGeneration

FourthGeneration

FifthGeneration

User-WrittenPrograms

MachineLanguages

PackagedPrograms

SymbolicLanguages

OperatingSystems

High-LevelLanguages

DBMSFourth-GenerationLanguages

MicrocomputerPackages

Natural &Object-Oriented

LanguagesMultipurpose

Graphic- InterfaceNetwork-EnabledExpert-Assisted

Packages

Trend:Toward Easy-to-Use Multipurpose Network-Enabled ApplicationPackages for Productivity and Collaboration

Trend:Toward Visual or Conversational Programming Languages andTools


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Operating Systems


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Functions of an OS

ResourceManagement

TaskManagement

UserInterface

FileManagement

Utilitiesand OtherFunctions


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The Role of the Operating System

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Operating Systems

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Perform common hardware functions Provide a user interface

Provide hardware independence

Manage system memory

Manage processing

Control access to system resources

Manage files


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Common Hardware Functions

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Accept keyboard input Retrieve data from disks

Store data on disks

Send data to output devices


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User Interface

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Command-based interfaces Graphical User Interfaces (GUIs)


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Hardware Independence

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Memory Management

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Network Capability

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Operating system may provide feature forconnecting to a network of computers


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Access to System Resources

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Protection against unauthorized access Logins and passwords

Maintaining log of access

Reporting attempt to breach security


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File Management

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OS provides file management features such as Making the file available when required

Preventing unauthorized access

Preventing simultaneous access by multiple users

Maintaining information about the files Search, delete, sort functions


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Utility Programs

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Types and Functions of

Applications Software


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General- Purpose Applications

Electronic Mail Word Processing

Presentation Graphics

Multimedia

Personal Information Manager

Groupware

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Enterprise Application Software

CustomerRelationship

Management

HumanResourceManagement

Accounting andFinancial

Management

Supply

ChainManagement

EnterpriseResourcePlanning

BusinessDecisionSupport


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Sources of Software

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Proprietary and OTS Software

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Organizing Data and Information


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The Database Approach toData Management


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Database Management System

Collection of interrelated data Set of programs to access the data

DBMS contains information about a particular enterprise

DBMS provides an environment that is both convenient andefficient to use

Database Applications:

Banking: all transactions, Airlines: reservations, schedules,Universities: registration, grades, Sales: customers, products,purchases, Manufacturing: production, inventory, orders, supply

chain, Human resources: employee records, salaries, tax deductions

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The Traditional Approach

In the early days, database applications werebuilt on top of file systems

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Drawbacks of using file systems


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g yto store data

Data redundancy and inconsistency Multiple file formats, duplication of information in different files

Difficulty in accessing data

Need to write a new program to carry out each new task

Data isolation multiple files and formats

Integrity problems Integrity constraints (e.g. account balance > 0) become part of

program code

Hard to add new constraints or change existing ones

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Drawbacks of using file systems


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a bac s o us g e syste s(cont.)

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Atomicity of updates Failures may leave database in an inconsistent state with

partial updates carried out

E.g. transfer of funds from one account to another shouldeither complete or not happen at all

Concurrent access by multiple users Concurrent accessed needed for performance

Uncontrolled concurrent accesses can lead to inconsistencies E.g. two people reading a balance and updating it at the same

time

Security problems


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Database Approach

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Database systems offer solutions to all the aboveproblems

Advantages of the Database


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gApproach

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Improved corporate use of data Reduced data redundancy

Improved data integrity

Easier modification and updates

Data independence from programs

Standard data access


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Database Structures

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Employee2

A

Empno Ename Etitle Dept

1

2 B

3 C

Relational Structure

Network StructureHierarchical Structure

Employee

3

Project BProject A

Dept Dname Dloc Dmgr

A

B

C

Employee2

Employee

1Project A

Employee1

Dept A Dept BDept

Project B


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Database Structures (cont)

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EastWest

Denver

FebActual Budget

Margin

Sales TV

VCR

TV

VCR

MultidimensionalDatabase Structure

AttributesCustomerBalanceOperationsDeposit

Withdraw

Bank Account Object

AttributesCredit LineMthly Statement

OperationsCalculate InterestPrint MthlyStatement

Checking AccountObject

AttributesCredit LineMthly Statement

OperationsCalculate InterestPrint MthlyStatement

Savings AccountObject

Object-OrientedDatabase Structure


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Database Development

User NeedsDescription

1. Data Planning

Enterprise Model

2. RequirementsSpecifications

3. Conceptual Design

4. Logical Design

Physical Models

5. Physical Design

Data Models

Logical Models


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Entity-Relationship Model

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Example of schema in the entity-relationshipmodel


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Entity Relationship Model (Cont.)

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E-R model of real world Entities (objects)

E.g. customers, accounts, bank branch

Relationships between entities

E.g. Account A-101 is held by customer Johnson

Relationship set depositor associates customers with accounts

Widely used for database design


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Relational Model

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Example of tabular data in the relational model

customer-name

Customer-id

customer-street

customer-city

account-number

Johnson

Smith

Johnson

Jones

Smith

192-83-7465

019-28-3746

192-83-7465

321-12-3123

019-28-3746

Alma

North

Alma

Main

North

Palo Alto

Rye

Palo Alto

Harrison

Rye

A-101

A-215

A-201

A-217

A-201

Attributes


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SQL

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Application programs generally access databasesthrough one of Language extensions to allow embedded SQL

Application program interface (e.g. ODBC/JDBC) which allowSQL queries to be sent to a database


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SQL

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SQL: widely used non-procedural language E.g. find the name of the customer with customer-id 192-

83-7465select customer.customer-namefrom customerwhere customer.customer-id = 192-83-7465

E.g. find the balances of all accounts held by thecustomer with customer-id 192-83-7465

select account.balancefrom depositor, accountwhere depositor.customer-id = 192-83-7465

anddepositor.account-number =account.account-number


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Database Users

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Users are differentiated by the way they expect tointeract with the system Application programmers interact with system through

DML calls

Sophisticated users form requests in a database query

language Specialized users write specialized database

applications that do not fit into the traditional dataprocessing framework

Nave users invoke one of the permanent application

programs that have been written previously E.g. people accessing database over the web, bank tellers,

clerical staff


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Transaction Management

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A transaction is a collection of operations thatperforms a single logical function in a databaseapplication

Transaction-management component ensuresthat the database remains in a consistent(correct) state despite system failures (e.g.,power failures and operating system crashes) and

transaction failures


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Storage Management

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Storage manager is a program module thatprovides the interface between the low-level datastored in the database and the applicationprograms and queries submitted to the system.

The storage manager is responsible to thefollowing tasks:

interaction with the file manager

efficient storing, retrieving and updating of data


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Selecting a DBMS

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Database size Number of concurrent users

Performance

Integration

Features

Vendor

Cost


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Communication Systems


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Communications

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Transmission of a signal by a medium fromsender to receiver

For effective communication, sender and receivermust understand the signals

They also must agree upon the rules forinterpreting the signal


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Communications

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Synchronous The message is received byreceiver instantaneously e.g. Voice, Phone

Asynchronous delay between time the messageis sent and time when it is received e.g. Mail, e-

mail


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Telecommunications

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Electronic transmission of signal e.g. Telephone,radio, TV

D i i


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Data communication

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Data Communication is a subset of Telecomwhich electronic collection, processing anddistribution of Data

The Data communication model consists of Sending computer system

Telecom device at senders end

Telecom device at receivers end

Receiving computer system

N k


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Networks

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A network consists of Communication media,devices and software required to connect two ormore computers / devices

Networking is done to share Data, Informationand resources

Geographically distant locations can shareinformation resources by networking

Telecommunications StrategicC bili i


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Capabilities

Overcome Geographic Barriers: Capture information aboutbusiness transactions from remote locations.

Overcome Time Barriers: Provide information to remote locationsimmediately after it is requested.

Overcome Cost Barriers: Reduce the cost of more traditionalmeans of communications.

Overcome Structural Barriers: Support linkages for competitiveadvantage.

C i i


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Communications

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Requires Media

Devices

Carriers

Services

T f M di


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Types of Media

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Suitability of a transmission media depends upon Purpose of Information system

Characteristics like transmission capacity andspeed of the media

Cost plays an important role in selection of amedia over another

T f M di


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Types of Media

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Twisted pair of copper wires

Coaxial cable

Fiber-optic cable

T i i


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Transmission

Microwave transmission

Cellular transmission

Infrared Transmission

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D i


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Devices

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Device, e.g, modem, multiplexers etc are requiredfor all kinds of electronic communication

Modems

Modulator does digital to analog conversion Demodulator does Analog to Digital conversion

Data transmission requires modulator at source anddemodulator at destination

Most systems provide for simultaneous bi-directional, or full duplex, transmission

C i A d S i


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Carriers And Services

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Telecom carriers provide the Telephone lines,satellites and other communication technology

In India, MTNL / Department of

Telecommunication provides the transmissionlines

VSNL and other ISPs provide Internet services

Services can be Switched or Dedicated


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Network and DistributedProcessing

Di t i t t i t i ti


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Direct point-to-point communication

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Computers connected by communicationchannels that each connect exactly twocomputers

Forms mesh or point-to-point network

Allows flexibility in communication hardware,packet formats, etc

Provides security and privacy becausecommunication channel is not shared

Connections in a point-to-pointt k


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network

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Number of wires grows with number of computers

Challenges

Connections between buildings can be prohibitive

Adding a new computer requires N - 1 newconnections

Broadcast Communication


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Broadcast Communication

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The sender computer broadcasts in a network This broadcast is heard by all the computers in

the network

If the Data is not meant for a computer, it is

passed onwards Received by the computer it is meant for

Network topologies


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Network topologies

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Networks may be classified by shape Three most popular:

Star

Ring

Bus

Network Topologies


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Network Topologies

Classification of Networks


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Classification of Networks

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Based on physical distance between thecomputers connected, the networks can beclassified as

Local Area Network

Wide Area Network Metropolitan Area Network

Wide Area Networks


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Wide Area Networks

Local Area Networks


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Local Area Networks

NetworkServer

SharedDatabase and

Software Packages

SharedPrinter

PCPC

PC PC PC

Internetwork Processor to OtherNetworks

Other E Business Networks


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Other E-Business Networks

Router

IntranetServer

Host System

IntranetServer

TheInternet

Fire wall

Fire wall

RouterExtranet

Client/Server Networks andNetwork Computing


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Network Computing

NetworkServer

Host SystemSuperserver

Client

User Interface

Application Processing Application ControlDistributed Database

Central database controlHeavy duty processing

Server Server

NetPC

Browser-basedUser Interface

Web OSApplication Software

Application

DBMS

DB

Communication software andProtocols


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Protocols

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Communication Software provide error checking,data formatting and maintenance of log

Communication Protocols define rules forcommunications

Network Protocols: The OSIArchitecture


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Architecture

Application Layer

Presentation Layer

Session Layer

Transport Layer

Network Layer

Data Link Layer

Physical Layer

SevenLayers of

the OSICommunicationsArchitecture

Communications Protocol


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Communications Protocol

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Standard model is Seven Layer OSI Model

TCP / IP Suite of protocols is the De-factoprotocol used in Internet

Consists of only four layers as opposed to 7 layerof OSI model

Other Protocols


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Other Protocols

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System Network Architecture Protocol used forIBM systems

Ethernet By Xerox corporation and others.Mainly used for LAN in a Bus topology

X.400 and X.500 are being used byinternational companies

Wireless protocols

Other devices in a Network


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Other devices in a Network

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Bridges - connects two or more networks with samecommunication protocols

Routers - determine preferred path to a finaldestination, and also perform other useful networkfunction, sometimes acting even as a Firewall

Gateways - link LANs or Networks that employdifferent higher level protocols

Switches - act as a bridge and a gateway combined.Where as Bridges and Gateways are able to connecttwo networks, switches are able to connect more

Telecommunication Applications


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Telecommunication Applications

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Linking Personal computers and mainframes Voice and Electronic Mail

Electronic Software and Document distribution

Telecommuting

Videoconferencing

EDI

Public Network Service

Distance Learning Specialized systems and services


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Internet Concepts

What Is Internet


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What Is Internet

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The Internet is a loose association of thousandsof networks and billions of computers and otherdevices across the world that all work together toshare information

Information Super Highway

Can be thought of as a mass transit system with afew main lines that intersect at certain points

Connecting to the main lines lines are branch lines,then bus lines, and ferry boats that spread out andcrisscross the area

What Is Internet


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What Is Internet

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By connecting to each other, these networkscreate a superfast pipeline that crisscrosses andextends to the rest of the world

The network is not equally well developed at

every point along the route Backbone has many intersecting points. If one

part fails or slows down, data can be quicklyrerouted over another part

This feature is called redundancy


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129

History of Internet

History of Internet


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History of Internet

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1957 - USSR launched Sputnik, first artificial earth

satellite.

1958 - US formed the Advanced Research ProjectsAgency (ARPA), within the Department of Defense(DoD) to establish US lead in science and technologyapplicable to the military

1961 - A series of independent research teams begandeveloping packet switching and the beginnings ofwhat would eventually become TCP/IP, the basicprotocol that defines how information is exchangedover the Net

History of Internet


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History of Internet

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1962 - MIT's J. C. R. Licklider develops a vision of what hecalled the "Galactic Network and writes a series ofmemos, thus sowing the first germ of the Internet

1967 - ARPA's Lawrence Roberts published his "Plan forthe ARPANet" computer network which proposed anarchitectural design for a worldwide network

1968 - The development of the first hardware was donethat could route data over the ARPANet.

1969 - The first tests were made at UCLA and then atStanford

History of Internet


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History of Internet

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1969 1972 - Test-tube Internet grew steadily but

unremarkably as government agencies, universities,and corporations continued to develop and hammerout protocols and architectures

1972 - Email and the Internet made their first publicappearances at the Internet ComputerCommunication Conference

1973 1974 - The protocol known as TCP/IPemerged in essentially its current form, although thesame group of collaborators would continue to refineit through the early 1980s

History of Internet


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History of Internet

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Once the protocols were in place, the various

developers formulated much of the software andservices that make up the Internet

Mid and late 1970s - The basic services forconnecting to files remotely (via Telnet), transferringfiles over the Net (via FTP), and sending andreceiving Electronic mail

1979 - The Usenet News System first appeared as anoffshoot of the rise of Unix.

1989 - The World Wide Web becomes operational

History of Internet


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History of Internet

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1990 - The U.S. government officiallydecommissioned ARPANet and National ScienceFoundation (NSF) took over the role of managingthe Internet backbone, which was then called theNSFNet

1995 - The NSF in turn withdrew, turning thebackbone over to a consortium of commercial

providers

Internet Growth Trends


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Internet Growth Trends

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1977: 111 hosts on Internet 1981: 213 hosts 1983: 562 hosts 1984: 1,000 hosts 1986: 5,000 hosts

1987: 10,000 hosts 1989: 100,000 hosts 1992: 1,000,000 hosts 2001: 150 175 million hosts

2002: over 200 million hosts By 2010, about 80% of the planet will be on the

Internet

Growth of Internet Hosts *

Sept. 1969 - Sept. 2002


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0

50,000,000

100,000,000

150,000,000

200,000,000

250,000,000

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Time Period

No.

ofHosts

The Internet was not known as "The Internet" until January 1984, at which time

there were 1000 hosts that were all converted over to using TCP/IP.

Chart by William F. Slater, III

Sept. 1, 2002

Dot-Com Bust Begins

Copyright 2002, William F. Slater, III, Chicago, IL, USA

Shrinking time lines


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To get a market of 50 Million People Participating: Radio took 38 years

TV took 13 years

Once it was open to the General Public, The

Internet made to the 50 million person audiencemark in just 4 years!!!

Statistics from the IITF ReportThe Emerging Digital EconomyDelivered to the President and the U.S. Public on April 15, 1998 by Bill Daley,Secretary of Commerce and Chairman of the Information Infrastructure Task Force

Who owns Internet ??


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No one.

The Internet Architecture Board (IAB) is responsible for defining theoverall architecture of the Internet providing guidance and broaddirection to the IETF

The Internet Engineering Steering Group (IESG) is a related

organization responsible for managing IETF activities and the Internetstandards process

The Internet Engineering Task Force (IETF) looks after the evolution ofthe Internet with a specific eye toward keeping the Internet runningsmoothly as a whole

The World Wide Web Consortium (W3C) - standards for HTML andother specifics of the Web

http://www.isi.edu/iab/http://coverage.cnet.com/Content/Features/Techno/Networks/ss01.htmlhttp://www.ietf.org/iesg.htmlhttp://www.ietf.org/http://www.w3.org/http://coverage.cnet.com/Resources/Info/Glossary/Terms/html.htmlhttp://coverage.cnet.com/Content/Features/Techno/Networks/ss03.htmlhttp://coverage.cnet.com/Content/Features/Techno/Networks/ss03.htmlhttp://coverage.cnet.com/Resources/Info/Glossary/Terms/html.htmlhttp://www.w3.org/http://www.ietf.org/http://www.ietf.org/iesg.htmlhttp://coverage.cnet.com/Content/Features/Techno/Networks/ss01.htmlhttp://www.isi.edu/iab/


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The Internet Society (ISOC) is a supervisory organization made up of

individuals, corporations, nonprofit organizations, and governmentagencies from the Internet community

The Internet Assigned Numbers Authority (IANA) and the InternetNetwork Information Center (InterNIC) lead the organizationsresponsible for assigning IP addresses and domain names, respectively

Regional and long-distance phone companies, backbone ISPs, cableand satellite companies, and governments all contribute in significantways to the telecommunications infrastructure that supports the Internet

But no one can wrest away total control of the Net, which is why it's notjust a communications medium, but a metaphor for the new global

economy
http://www.isoc.org/http://www.iana.org/iana/http://www.internic.net/http://www.internic.net/http://coverage.cnet.com/Content/Features/Techno/Networks/ss04.htmlhttp://coverage.cnet.com/Content/Features/Techno/Networks/ss01.htmlhttp://coverage.cnet.com/Content/Features/Techno/Networks/ss01.htmlhttp://coverage.cnet.com/Content/Features/Techno/Networks/ss04.htmlhttp://www.internic.net/http://www.internic.net/http://www.iana.org/iana/http://www.isoc.org/


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How Does Internet Work


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The secret of the Net is a network protocol called

TCP/IP

The transmission control protocol (TCP) and theInternet protocol (IP) together form the basis of theInternet

Every computer that hooks to the Internetunderstands these two protocols and uses them tosend and receive data over the network

TCP/IP creates what is called a packet-switchednetwork



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First, TCP breaks down every piece of data intosmall chunks called packets, each of which iswrapped in an electronic envelope with Webaddresses for both the sender and the recipient



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o oes te et o

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The IP protocol then figures out how the data is

supposed to get from point A to point B by passingthrough a series of routers

Each router examines the destination addresses ofthe packets it receives and then passes the packets

on to another router as they make their way to theirfinal destination

As the packets arrive, TCP takes over again,identifying each packet and checking to see if it's

intact. Once it has received all the packets, TCPreassembles them into the original



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TCP/IP is the most important of a long list of Internet protocols

E-mail uses SMTP

Telnet (Telnet Protocol) facilitates login to a computer host toexecute commands

FTP (File Transfer Protocol) Transfers text or binary filesbetween an FTP server and client

Usenet (Network News Transfer Protocol or NNTP) DistributesUsenet news articles

HTTP (Hyper Text Transfer Protocol) Transmits hypertext overnetworks. This is the protocol of the WWW


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Are Internet & WWW same ?

Are Internet & WWW Same ?


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Although the terms Web and Internet are often used

synonymously, they're actually two different things

The Internet exists independently of the Web, but theWeb can't exist without the Internet

The Internet is the global association of computersthat carries data and makes the exchange ofinformation possible

The World Wide Web is a service on Net - a collectionof interlinked documents that work together using aspecific protocol called HTTP

The World Wide Web


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The Web began in March 1989, when Tim Berners-

Lee of the European Particle Physics Laboratory (aorganization of European researchers better knownby its original name CERN, or Conseil Europen pourla Recherche Nucleaire) proposed the project as ameans to better communicate research ideas amongmembers of the far-flung organization

The Web uses a metaphor of individual pages,usually combined to make up sites. Web pages are

written in HTML, or Hypertext Markup Language,which tells the Web browser how to display the pageand its elements

The World Wide Web
http://coverage.cnet.com/Resources/Info/Glossary/Terms/html.htmlhttp://coverage.cnet.com/Resources/Info/Glossary/Terms/browser.htmlhttp://coverage.cnet.com/Resources/Info/Glossary/Terms/browser.htmlhttp://coverage.cnet.com/Resources/Info/Glossary/Terms/html.html


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The defining feature of the Web is its ability to

connect pages to one another- as well as to audio,video, and image files- with hyperlinks

Despite its cool hyper linking ability, the early Weblabored for a while in obscurity, a little-known

alternative to the less technically advanced Gopherprotocol

in February 1993, Marc Andreessen, then developingfor the National Centre for Supercomputing

Applications, introduced the first graphical Webbrowser, called Mosaic

The World Wide Web


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The Web is based on a set of rules for exchanging text,

images, sound, video, and other multimedia files, which iscollectively known as HTTP, or hypertext transfer protocol.

Web pages can be exchanged over the Net becausebrowsers (which read the pages) and Web servers (which

store the pages) both understand HTTP

But everything would still be chaos if the Web didn't havean addressing scheme that every computer on the networkunderstands.

To address, this problem, a system of IP Address wasdeveloped

The World Wide Web
http://coverage.cnet.com/Resources/Info/Glossary/Terms/http.htmlhttp://coverage.cnet.com/Resources/Info/Glossary/Terms/http.html


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An IP address is a 32 Bit (4- to 12-digit) number that

identifies a specific computer connected to theInternet. The digits are organized in four groups ofnumbers (which can range from 0 to 255) separatedby periods

Depending on how your ISP assigns IP addresses,you may have one address all the time or a differentaddress each time you connect

Web servers have the same kind of addresses: if you

type http://202.54.1.30/ in your browser, you'll get thesame result as if you had typed http://www.vsnl.com/

The World Wide Web


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Internet domain names are the next level of Internet addressing,

just as the street name is followed by the city and state.

Domain names create a single identity for a series of computersused by a company or an institution. So while there may be 38servers at a given company, each with its own IP address, theyall share a common domain name, such as CNET.COM

The domain name identifies all the computers in a group, but fora specific page stored on any of those computers, a moreprecise address is required

Thats why Every Web page on the Internet has its own uniqueaddress, known as a Uniform Resource Locator (URL)

The World Wide Web
http://coverage.cnet.com/Resources/Info/Glossary/Terms/url.htmlhttp://coverage.cnet.com/Resources/Info/Glossary/Terms/url.html


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protocol://host/path/filename

http://www.house.gov/agriculture/schedule.htm

Protocol: http

Host computer name: www Second-level domain name: house

Top-level domain name: gov

Directory name: agrictulture File name: schedule.htm


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Driving Technologies

Web Browsers


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A browser is a software program that allows usersto access and navigate the World Wide Web.There are two types of browsers:

Graphical: Text, images, audio, and video are

retrievable. Navigation by Click Text: text-only mode. Navigation by highlighting

emphasized words with the arrow up and downkeys

Web Browsers Plug-ins


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Software programs in order to enhance browsercapabilities.

When the browser encounters a sound, image or

video file, it hands off the data to other programs,called plug-ins, to run or display the file. Workingin conjunction with plug-ins, browsers can offer aseamless multimedia experience. Many plug-ins

are available for free.

HTML


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Hyper Text Mark-up Language, or HTML is used to

create hypertext for the Web.

With HTML, tags are placed within the text toaccomplish document formatting, visual features suchas font size, italics and bold, and the creation of

hypertext links.

Graphics, Multimedia components may also beincorporated into an HTML document.

The World Wide Web Consortium coordinates theefforts of standardizing HTML

Limitations of HTML


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Can serve only Static pages

Restricts the web site to be only informative

Interactivity is not possible

Use of web is limited to Broadcast media

XML


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eXtensible Markup Language enables designers to

create their own customized tags to providefunctionality not available with HTML

XML is a language of data structure and exchange

Allows developers to separate form from content

In May 1999, the W3 Consortium recast HTML 4.0 asan XML application called XHTML

This move will have a significant impact on the futureof both XML and HTML

Client side Scripting


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Small programs embedded within an HTML page, or

called externally from the page, to enhance thepage's functionality

Examples of ClientScript include moving tickers, drop-down menus, real-time calendars and clocks, andmouse-over interactions

JavaScript created by Netscape Communications

supported by Netscape as well as Internet Explorer

VBScript - created by Microsoft Subset of Visual Basic Supported mainly by Internet Explorer

Server Side Scripting


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Programs that run on the Server side

Help make the content truly dynamic

Interaction with Databases is possible

This also makes transactions possible.

CGI (Common Gateway Interface)


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A CGI program, or script, is a program designed to

accept and return data that conforms to the CGIspecification

The program can be written in any programminglanguage, including C, Perl, and Visual Basic Script

A common use for a CGI script is to process aninteractive form on a Web page, e.g For example,filling a form ordering a book through InterlibraryLoan.

The script processes your information and sends it to

a designated e-mail address in the Interlibrary Loandepartment

ASP / JSP


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Active Server Pages is Microsofts way of adding

interactivity to sites

JSP is Suns answer to ASP

Every time a page is requested, Server runs the

script and generates the page afresh While ASP Runs on IIS, JSP can run on Apache

server, Java Server

Java


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Java is an object-oriented programming language

similar to C++.

Developed by Sun Microsystems, the aim of Javais to create programs that will be platform

independent

The Java motto is, "Write once, run anywhere." Aperfect Java program should work equally well on

a PC, Macintosh, Unix, and so on, without anyadditional programming

Java


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Web-based Java applications are usually in the form

of Java applets. These are small Java programscalled from an HTML page that can be downloadedfrom a Web server and run on a Java-compatible Webbrowser

A few examples include live news feeds, movingimages with sound, calculators, charts andspreadsheets, and interactive visual displays.

Java applets can tend to load slowly, but

programming improvements should lead to ah t d l di ti

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