INTERNET SERVICES

Back in the days when dinosaurs roamed the earth (in 1972), a guy named Ray Tomlinson invented an email program to send messages across what was called a distributed network.

Email

Email shortened term for

“electronic mail” a system of receiving,

sending, and storing electronic messages

text messages that may contain files, images, or other attachments sent through a network to a specified individual or group of individuals

Some Email Providers:Gmail, YahooMail, Outlook, Hot Mail, GraphicMail, ClickMail, Zoho Mail, AIM Mail, iCloud Mail, Shortmail, and Inbox.

Figure 1: Different email providers

Email the first portion all e-mail

addresses is the alias, user, group, or department of a company

next, the @ (at sign) is used as a divider in the e-mail address and is always required for all SMTP email addresses

Simple Mail Transfer Protocol (SMTP) - communications protocol that sends e-mail messages from one server to another over port 25.

last portion is the domain name

dont_reply@ email.com

alias

domain

helloworld @ email.com

Figure 2: Email address

The World Wide Web is a huge collection of hypertext documents and hypermedia. It has facilitated easy access to information over the Internet.

World Wide Web

Word Wide Web Invented by Sir Timothy John

"Tim" Berners-Lee, a British computer scientist

a system of Internet servers that support specially formatted documents. The documents are formatted in a markup language called HTML that supports links to other documents, as well as graphics, audio, and video files.

This means you can jump from one document to another simply by clicking on hot spots.

Internet is the means to access this set of interlinked documents.

Figure 3: Timothy John Berners-Lee

Word Wide Web The network of web servers

serves as the backbone of the World Wide Web. The Hypertext Transfer Protocol (HTTP) is used to gain access to the web.

A web browser makes a request for a particular web page to the web server, which in turn responds with the requested web page and its contents.

It then displays the web page as rendered by HTML or other web languages used by the page. Each resource on the web is identified by a globally unique identifier (URI)

Figure 4: Hypertext Transfer Protocol

Word Wide Web Each web page has a unique

address, with the help of which a browser accesses it. With the help of the domain name system, a hierarchical naming system for computers and resources participating in the Internet, the URL is resolved into an IP address.

Presence of hyperlinks, the worldwide availability of content and universal readership are some of the striking features of the World Wide Web. The interlinked hypertext documents form a web of information.

Figure 5: Hyperlink

Word Wide Web Hyperlinks present on web

pages allow the web users to choose their paths of traversal across information on the web.

They provide an efficient cross-referencing system and create a non-linear form of text.

The information on the web is available 24/7 across the globe. It is updated in real time and made accessible to web users around the world. Except for certain websites requiring user login, all the other websites are open to everyone.

Figure 6: Login interface

FTP, File Transfer Protocol, is a protocol through which internet users can upload files from their computers to a website or download files from a website to their PCs.

File Transfer Protocol

FTP File Transfer Protocol (FTP) is a

standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet.

An FTP client is a program that allows you to easily move files from one computer to another.

In the case of creating a Web site, this means that if you create the pages for your site on your computer, either using a text editor or some other Web page editor, then you will need to move it to the server where your site will be hosted. FTP is the main way to do this.

Figure 7: File Transfer Protocol

FTP TCP and IP are the two major

protocols that keep the internet running smoothly. TCP manages data transfer while IP directs traffic to internet addresses. FTP is an underling of TCP and shuttles files back and forth between FTP server and FTP client. Because FTP requires that two ports be open--the server's and the client's--it facilitates the exchange of large files of information.

Figure 8: How FTP works

FTP First, you as client make a TCP

control connection to the FTP server's port 21 which will remain open during the transfer process. In response, the FTP server opens a second connection that is the data connection from the server's port 20 to your computer.

Using the standard active mode of FTP, your computer communicates the port number where it will stand by to receive information from the controller and the IP address--internet location--from which or to which you want files to be transferred.

Figure 8: FTP diagram

FTP Clients

SmartFTP

Cyberduck

Filezilla

Transmit

FireFTP WinSCPFigure 9: FTP clients

The first online chat system was called Talkomatic, created by Doug Brown and David R. Woolley in 1974 on the PLATO System at the University of Illinois. It offered several channels, each of which could accommodate up to five people, with messages appearing on all users' screens character-by-character as they were typed.

Online Chat

Online Chat may refer to any kind of

communication over the Internet that offers a real-time transmission of text messages from sender to receiver. Chat messages are generally short in order to enable other participants to respond quickly.

Thereby, a feeling similar to a spoken conversation is created, which distinguishes chatting from other text-based online communication forms such as Internet forums and email.

Figure 10: Chat presented in a Bubble quote

Online Chat Online chat may address point-to-

point communications as well as multicast communications from one sender to many receivers and voice and video chat, or may be a feature of a web conferencing service.

Online chat in a less stringent definition may be primarily any direct text-based or video-based (webcams), one-on-one chat or one-to-many group chat (formally also known as synchronous conferencing), using tools such as instant messengers, Internet Relay Chat (IRC), talkers and possibly MUDs.

Figure 11: Video chat

Major search engines such as Google, Yahoo (which uses Google), AltaVista, and Lycos index the content of a large portion of the Web and provide results that can run for pages - and consequently overwhelm the user.

Search Engines

Search Engines A web search engine is a

software system that is designed to search for information on the World Wide Web.

The search results are generally presented in a line of results often referred to as search engine results pages (SERPs).

The information may be a specialist in web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories.

Figure 12: Major web search engines

Search Engines It is a set of programs that

includes: Spider (or crawler) that goes to

every page or representative pages on every Web site that wants to be searchable and reads it, using hypertext links on each page to discover and read a site's other pages

A program that creates a huge index (sometimes called a "catalog") from the pages that have been read

A program that receives your search request, compares it to the entries in the index, and returns results to you

Figure 13: Spider (web crawler)

Search Engines Web search engines work by

storing information about many web pages, which they retrieve from the page's HTML. These pages are retrieved by a Web crawler (sometimes also known as a spider) — an automated Web browser which follows every link on the site.

The contents of each page are then analyzed to determine how it should be indexed (for example, words can be extracted from the titles, page content, headings, or special fields called meta tags).

Figure 14: Spider (web crawler)

Search Engines When a user enters a query

into a search engine (typically by using keywords), the engine examines its index and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document's title and sometimes parts of the text.

Most search engines support the use of the boolean operators AND, OR and NOT to further specify the search query. Boolean operators are for literal searches that allow the user to refine and extend the terms of the search. The engine looks for the words or phrases exactly as entered.

Figure 15: Google search query

Search Engines The usefulness of a search

engine depends on the relevance of the result set it gives back. While there may be millions of web pages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others.

Most search engines employ methods to rank the results to provide the "best" results first. How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another.

Figure 16: Page rank system

What is an Internet server?

หรอ เวบเซรฟเวอร (Web Server) คอเครอง คอมพวเตอร ททำ�ก�รตดตง Software เกยวกบ

Server ททำ�หน�ทบรก�รและสงขอมลใหกบ Client ททำ�ก�ร Request ขอมล และ Web Server จะทำ�ก�ร

Response เพอสงผลลพธไปยง Client โดย Web Server ทว ๆ ไปทเร�คน ๆ กนดคอตดตง Software ท

ชอว� IIS (Internet Information Services) และApache โดย Service เหล�นจะบรก�รขอมลผ�น Port : 80 และรบสงขอมลผ�น Web Browser สวนม�ก

Web Server and Web Hosting

Web Server and Web Hosting Web Hosting คออะไร ?

เวบโฮสตง (Web Hosting) คอบรก�รพนททอยบน Web Server ท ผใหบรก�รนำ� Server ของตวเองไปตงเปน Web Server และให

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จ�กรปเปนก�รอธบ�ยก�รทำ�ง�นของ Web Server และ Web Hosting   ซงจะคอยทำ�หน�ทบรก�รขอมล Request และResponse  ค�ต�ง ๆ จ�ก Client  โดยท Client นนจะไมเจ�ะจงว�

จะใชระบบปฏบตก�รอะไร เพยงแคส�ม�รถสอส�รกนต�มม�ตร�ฐ�น ของ Protocol ทกำ�หนดขนเท�นน

เครอง Computer ทจะนำ�ม�ทำ�เปน Web Server

มคณสมบตอย�งไรคณสมบตของเครองคอมพวเตอรทจะนำ�ม�ทำ�เปน Web Server  นน จะ

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ไดโดยเฉพ�ะ และเครอง Server ส�ม�รถทำ�ง�นไดเปนสบป (ถ�อยในสภ�พแวดลอมทเหม�ะสม) แตทงนก�รใชง�นจะตองมก�รซอมบำ�รงต�มระยะเวล�ท

กำ�หนด เชน HDD ควรจะเปลยนทก ๆ 2-3 ป และควรจดทำ� ระบบ Backup  ใหเหม�ะสม เผอปองกนก�รศนยห�ยของขอมล

ตวอย�งของเครอง Computer ทจะนำ�ม�เปนWeb Server

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เองไดแลว และเครอง Server ทนยมใชจะเปนแบบ Rack ( แทงสเหลยมย�วๆ) เพร�ะถ�ใชแบบ Rack ค�บรก�รทจะนำ� Server ไปว�งไวท Data Center (อนเตอรเนตคว�มเรวสง) กจะถกลงดวยเชนเดยวกน และอก

ประเภทหนงคอแบบ Tower ซงเหมอน PC ทว ๆ ไป และตวนค�บรก�รก�รว�ง ท Data Center กจะเแพงเกอบเท�ตวของ Server แบบ Rack

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และนำ�ไปว�งไวท Data Center อก เพร�ะไดมเทคโนโลยใหม ๆ เกยวกบVM , VPS , และ Cloud Server และอน ๆ ทส�ม�รใหเร�ม Web Server

เปนของตวเองในร�คทตำ�ม�ก และ ไมตองลงทนในก�รซอเครอง Server เลย

เครอง Server แบบ Rack , แบบTower

Software ทใชสำ�หรบตดตงบน Server เพอเปลยนใหเปน Web Server

สำ�หรบ OS หรอระบบปฏบตก�รทใชง�นสวนใหญแลว จะมอย 2 ตว คอ Windows Server และ Linux

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เชนเดยวกน

Software ทใชสำ�หรบตดตงบน Server เพอเปลยนใหเปน Web Server