Definition of a Computer Component

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A component of a computer is also referred to as computer hardware.
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When talking about computers, the term "component" refers to a basic physical element that's required by the computer to function. A component of a computer is also referred to as computer hardware. Every personal computer, whether it's a Windows or Mac system, requires the same basic components to run. Software and firmware are also required to make a computer useful, but they are not generally included on lists of computer hardware components.


Main Computer Hardware Parts and Functions

Experts in computer science define five main components that are found in every personal computer. Perhaps the most important is the internal memory component. It stores data and instructions for programs as they execute. Next are two components within the computer's processor: the datapath and control components. The datapath component manages movement of data, while the control component directs operations of the datapath and memory.

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Two additional computer components support interaction between the computer and its human users. The input component consists of all the peripherals, or external devices, used to pass data to the computers. Keyboards, mice and networks are examples of input components. The output component communicates information from the computer back to the user. Examples of output component devices include monitors, printers and external drives. Networks also serve as output devices since they provide two-way communication between computer and user.


Additional Computer Components

There is no one definitive list of computer components. Different sources may give alternative definitions of the main components. Some list the motherboard, which is the circuit board that houses the computer's central processing unit (CPU). The power supply may be included as well as the video card, which is an output device that processes graphics for display. The number of items included on a list of computer components usually depends on the level of detail. Shorter lists that don't include a lot of specific devices are based on an overview approach.


The Role of Software

The programs that run on a computer are referred to as software. The relationship between a computer and the software it runs is similar to the relationship between a television set and the programming it plays. The software is not strictly part of computer hardware parts and functions, but it allows the computer to do useful things. System software performs all the operations the computer needs to run while application software performs specific functions like word processing and internet browsing.


Very low-level programs that make a piece of hardware work are often referred to as firmware. This name reflects the fact that the code is dedicated to the hardware and usually embedded in read-only memory so it's difficult to change. Peripheral devices like routers, cameras and scanners depend on firmware for operation.

Building Your Own Computer

One of the best ways to become familiar with the components of a computer is by building your own. Computer hobbyists have long preferred to assemble their own computers rather than purchasing factory-assembled models. As a result, there are scores of YouTube videos and online articles with instructions and advice. If you buy components online from a single retailer like PC Parts Picker, you have a better chance of ensuring that they'll all be compatible.


Factory-built computers often including operating system software like Windows or Linux. When you build your own, you'll need to purchase all system and application software separately. You have the freedom of tailoring your software choices. If you're building a gaming or streaming computer, you might not care about installing Microsoft Office or other productivity applications that sometimes come preinstalled when you purchase a computer or laptop.