The Amazing Computer

Before we begin our journey into the computer world there are some definitions that will help us along the way (and more will follow).PARTS OF A COMPUTER MACHINEDefinitions:Computer: an electronic device that processes data, converting it into information that is useful to people.Computer system: consists of four parts hardware, software, one or more users, and data.Hardware: the physical devises that make up the computer, i.e. anything you can touch. Device is any piece of hardware.Software: a set of instructions that makes the computer perform tasks. Software tells the computer what to do. Some programs exist primarily for the computer’s use, other types of programs exist for you (the user), letting you perform tasks such as creating documents. The term program refers to any piece of software.User: you!Data: individual facts or bits of information. The computer reads and stores data of all kinds. Ex. words, numbers, images, or sounds.

LOOKING INSIDE THE MACHINEProcessing: the procedure that transforms raw data into useful information.To perform this transformation, the computer uses two components: the processor and memory.Processor: the “brain” of the computer; it organizes and carries out instructions that come from either the user or the software.

Microprocessors (chips): processor consists of one or more of these.Motherboard: a rigid rectangular card containing the circuits that connects the processor to other hardware.Central Processing Unit (CPU): refers to a computer’s processor. People often refer to a computer system by the type of CPU they contain. A “Pentium 4” system, for example, uses a Pentium 4 microprocessor as its CPU.

Memory: like an electronic note pad inside the computer. When you run a program, it is loaded and runs from memory. Data used by the program is also loaded into memory for fast access. As new data is entered into the computer it is also stored in memory – but only temporary. The most common type of memory is called Random Access Memory (RAM).Random Access Memory (RAM): memory usually means RAM. One of the most important factors affecting the speed and power of a computer is the amount of RAM it has. The more RAM a computer has, the more it can do and the faster it can perform certain tasks. The most common measurement unit for describing a computer’s memory is the byte. Byte: the amount of memory it takes to store a single character, such as a letter or a number.When referring to a computer’s memory, the numbers are usually so large that it is helpful to use terms such as kilobyte (KB), megabyte(MB), gigabyte (GB) and terabyte (TB) to describe the values.See table below.

Input and Output DevicesInput devices: accept data and instructions from the user and from other computer systems (such as a computer on the internet). Examples are keyboard, mouse, trackballs, microphones.Output devices: to present processed data to the user. Examples are monitor, printer.

StorageThe purpose of storage is to hold data permanently. “You may think of storage as an electronic file cabinet and RAM as an electronic worktable. When you need to work with a program or a set of data the computer locates it in the file cabinet and puts a copy on the table. After you have finished working with the program or data, you put it back into the file cabinet. The changes you make to data while working on it replace the original data in the file cabinet (unless you store it in a different place).” (Computing Fundamentals 5th edition, 2003)

There are many types of storage devices, disks, CD’s, removable hard drives, and USB keys.