Ever wondered how the computer works? Here’s how.


A computer is a machine (hardware) that receives and processes data according to the instructions given to it, and after the data has been processed, the results of the processing are usually sent to an output device.


The input devices for feeding the computer with data and instructions can be a keyboard, mouse, scanner, or may be generated internally from ‘applications’ stored as programmed instructions (software). The processing of the data is done by the central processing unit (CPU), which is the heart of the computer. The output devices can be a screen (monitor), printer, plotter, speakers, ports, or another computer.

Parts of a computer

Parts of a computer


A CPU is on a chip called a microprocessor (about 1 inch square in size). This is basically your Intel pentium chip. Often referred to as the brains of a computer, the CPU handles most of the operations that are required of the computer by processing instructions and sending signals out, checking for connectivity, and ensuring that operations and hardware are functioning properly. It acts as a messenger to major components such as RAM, the monitor, and disk drives.


Hard Disk Drivepenny

The hard drive is where all your programs and documents are stored. Anytime you install software or save a file, it gets written to the hard drive. The hard drive also reads any data you are trying to access, such as when you open a text document or play an MP3. Think of it like a library and a librarian all mixed up in one. This is permanent storage (at least until you uninstall software or delete a file). The hard drive is normally signified by the drive letter “C”. Today’s hard drives can store a HUGE amount of information. A new computer might have a hard drive that will hold 500 GB’s!



Random access memory (RAM) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the processor. The contents of RAM are lost when the computer power is turned off. The more RAM a computer has, the more capacity the computer has to hold and process large programs and files.




Your computer couldn’t work without the motherboard. This vital circuit board ties everything together! It allows every part of your computer to receive power and communicate with each other. Everything that runs the computer or enhances its performance is either part of the motherboard or plugs into one of its expansion slots or ports. If a component is not connected to the motherboard, your computer won’t know that it’s there.


pennyROM and BIOS

Read only memory (ROM) chips, located on the motherboard, contain instructions that can be directly accessed by the microprocessor or CPU. Data transfer from ROM is faster than any disk, but slower than RAM. The instructions and data in the ROM chip that control the boot process and the computer hardware are known as the basic input/output system (BIOS), sometimes called firmware.

The ROM chip that contains the firmware is called the ROM BIOS chip. It is also referred to as ROM BIOS, or simply BIOS, and is usually marked “BIOS” on the motherboard. The responsibility of the BIOS is to serve as a liaison between the computer operating software and the various hardware components that support it. In simple terms, the BIOS chip wakes up the computer when you turn it on and reminds it what parts it has and what they do!


Sound and Video Cardsrudy

Sound and Video Cards are Output Devices. They contain special circuits that allow your computer to play sounds and display graphics on your monitor.