The physical part of a computer is called the computer hardware as differentiated from a software which is the computer programs and data that run within the hardware. The hardware is rarely changed compared with the software and data which are “soft” meaning that they are promptly created, changed or deleted on the computer. A special software that is hardly ever changed and is kept on hardware devices like read-only memory(ROM) where it is not quickly modified(Thus the term “firm”).

Most computer hardware is not visible to normal users because they are implanted as enclosed systems in cars, microwave ovens, ECG machines, CD players and other household items.

Personal computer hardware

A common personal computer contains a case or chassis in desktop or tower sizes and the parts enumerated below :
-Motherboard or system board consisting of slots for expansion cards and holding parts which includes :
-Central processing unit (CPU)
-Random Access Memory (RAM) – for execution of the program and short term storage of data, so that no time will be wasted in accessing the hard drive to locate something. The higher the RAM the faster the PC.
-Power supply – a case that encloses the transformer, voltage control and the fan
-Storage controllers which are responsible for controlling hard disk, floppy disk, CD-ROM and other drives; the controllers are directly placed on the motherboard or on expansion cards.
-Video display controller creates the output for the display of the computer
-Computer bus controllers connects the computer to outside tangible devices like printers or scanners
-Some type of removable media writer:
-CD – the most used type of removable media which may be cheap yet fragile
-Floppy disk
-Zip drive
-USB Flash Drive
-Tape drive – used for backing-up and long-term storage
-Internal storage – stores data within the computer for future use
-Hard disk – used for medium-term data storage
-Disk array controller
-Sound card – converts signals from the system board into analog voltage levels, consisting of terminals to attach speakers
-Networking – allows connection to the Internet and other computers
-Modem – used for dial-up connections
-Network card – used for DSL/Cable internet and other computers
-Other connecting devices
Likewise, hardware can also consist of external parts of a computer system. The following are either typical or very ordinary
-Input or Input devices
-Pointing devices
-Gaming devices like joystick or gamepad
-Image, Video input devices such as scanner or webcam
-Audio input devices like the microphone
-Output or Output devices like printers, monitors