Computer hardware means the physical part of a computer and it is totally different from computer software or computer programs and data that are used within hardware. The hardware of a computer is rarely changed as compared with software and data, which are readily shaped, modified or erased on the computer. Normal users do not see most computer hardware as it is enclosed as embedded systems in automobiles, microwave ovens, compact disc players and many other household appliances.

A typical personal computer consists of a case in desktop and other different parts. Motherboard or system board with slots for expansion cards and holding parts including Central processing unit (CPU) , Random Access Memory (RAM) for program execution and short-term data storage. It also consists of PCI bus, PCI-E or AGP bus, ISA bus, USB and power supply that holds a transformer, voltage control and fan.

The storage controllers of IDE, SATA, SCSI or other type, that control hard disk, floppy disk, CD-ROM and other drives. Video display controller that produces the output for the computer display Computer bus controllers to connect the computer to external peripheral devices such as printers or scanners.

Some type of a removable media writer includes CD, CD-ROM Drive, CD Writer, DVD, DVD-ROM Drive, DVD Writer, DVD-RAM Drive, Floppy disk, Zip drive, USB Flash Drive, Tape drive - mainly for backup and long-term storage, Internal storage that keeps data inside the computer for later use. Hard disk is used for medium-term storage of data. Sound card translates signals from the system board into analog voltage levels and has terminals to plug in speakers. Networking is used to connect the computer to the Internet and/or other computers and modem for dial-up connections.

In addition, hardware can include external components of a computer system. Mainly the computer input devices includes keyboard, pointing devices, mouse, trackball, gaming devices, joystick, gamepad image, video input devices, image scanner, web cam, audio input devices and microphone. Output devices consist of printer, monitor, audio output devices, speakers and headset.