The function of computer hardware components varies depending on the component in question. Hardware components you’ll find in any system include things like the motherboard, CPU, RAM, hard drive and network cards. Each of them server different purposes and have different functions…

Motherboard
The motherboard is the circuit board device which all hardware components must connect to in order to be able to communicate with one another. The motherboard connects and distributes information to all components along with managing power requirements.

Hardware components such as RAM, network cards, graphics cards and the CPU are all connected to the motherboard.

Processor (CPU)
The central processing unit (CPU) carries out the actual computing work on a system. It’s considered the brain of the system as it executes all the instructions necessary in order for the operating system to run and communicate with all software and hardware components.

Power Supply
A PSU (power supply unit) device supplies internal components with power. It converts alternating current (AC) from the standard wall socket in to a more stable direct current (DC) which becomes usable by the computer components. Power supply units have varying voltage ratings depending on the power requirements of any given system. The 3 main voltage ratings are 12V, 5V and 3.3V.

Fans and Heat Sinks
Most computers have fans which help to keep system components cool. These fans are powered by the PSU and ensure the system runs reliably. When a system boots, you’ll often hear fans run at maximum speed temporarily until the operating system and software instructs them to slow down.

Heat sinks server the same purpose and are placed over CPUs or graphic cards in order to keep them from overheating (which would leave to performance issues or system crashes). Heat sinks are designed to  draw heat away from critical components such as a CPU and dissipate the heat through the rest of the computer. Heat sinks generally have fans built in to them. If system components are still running too hot, some high end systems or supercomputers are water cooled.

BIOS
The BIOS (stands for ‘basic input/output system) is read only memory located on all motherboards that allows users to access and set up the computer system at the most basic level (through a command line interface). Through the BIOS, users can change the boot order (i.e. boot from a specific hard drive first above another hard drive), view system temperatures, view voltages and fan speeds and load an operating system in networking mode or safe mode (minimum possible state the operating system can start in – usually used to troubleshoot system problems).

Hard Drive
All systems need to be able to store information somewhere. RAM is for short term use only which means that when the system is switched off, anything in RAM is lost. Hard drives are therefore needed to store things permanently or over a longer term.

Mechanical hard drives tend to take a lot of time to spin up and fetch data whereas newer solid-state drives (SSDs) have no moving parts, so they’re much quicker however they’re also more expensive.

Hard drives connect to the computer using different interfaces such as SATA (Serial Advanced Technology Attachment) or the older PATA interface (Parallel Advanced Technology Attachment, also formerly known as IDE). If the motherboard only has SATA connections, a PATA drive will not work in the system. Similarly if an older system only has PATA connections, a newer SATA will not be compatible.

Ports
Virtually all motherboards come with ports available for connecting peripheral devices such as USB ports (universal serial bus). These allow users to attach portable storage media or hardware to their system such as usb sticks, scanners, cameras, printers etc.. Parallel and serial ports were also commonly used up until the early 2000’s and these were used to connect printers, keyboards and mice to a system.

RAM
Random access memory (RAM) is a computer’s internal, short term memory. This memory is used by the operating system and all applications which are loaded in to memory for quick access. If the memory becomes full (i.e. if a user is running multiple, high performance applications) the system will swap between using RAM and storage on the hard disk drive which slows down performance. This is why increasing the amount of RAM in a system is usually the quickest way to improve performance in an older system.

Network Cards and Graphics Cards
Wireless and wired networking cards enable a system to connect to the internet or a local network. These cards are plugged in to an expansion slot on the motherboard although most modern motherboards actually come with in-built NICs (network interface cards). The NIC itself typically houses the RJ45 (ethernet) port we’re all familiar with.

Graphics cards can improve the quality and performance of a computer system when it comes to rendering images on a users monitor. When working with 3D media, video editing or CAD design applications, these applications tend to require lots of image related processing power which the CPU can’t handle. A dedicated graphics card can process this data much faster than a CPU.