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We all use them on a daily basis without really knowing what the parts of a computer are. I guess you got here as now you do want to know! This short guide is designed to give you a very basic look at the parts of a computer and the basic functions of the different parts in there. It is also useful to know what is inside of a computer if you are looking at upgrading in the future so you know which parts you are looking at!

If you take the side off your computer you will see something similar to the image below. It is difficult to get a good photo of the inside of a computer due to the number of cables etc. We have tried to label them the best we can and if you click the image you will be able to see a larger image. The inside of a computer does vary from computer to computer but they all contain the basics which we will now go through.

The Parts Of A Computer

The Motherboard

When it comes to ranking different parts of a computer this would be right there near the top standing out above the rest. Without the motherboard the computer would simply not work.

This is the main PCB (Printed Circuit Board) that controls all the other hardware on your computer and brings them all together and allows them to communicate with each other. It also provides connectors for other things you may want to connect such as USB ports, graphics cards, additional storage as well as many other things. It is also sometimes referred to as the system board or mobo.

The motherboard contains things like the processor socket, Memory  slots (DIMMS), PCI Slots, Sata connectors. Click the below image for a larger image.

parts of a computer - motherboard

The Processor

profrontThe processor is considered the brain of the computer. It is the part that interprets and executes the commands of most of the computers hardware and software and performs all the calculations necessary to run your word processing packaging or access the web. The 2 popular processor manufacturers you will likely have heard of are Intel and AMD.

The processor is connected to the motherboard via the motherboard CPU socket. A computer processor tends to get very hot (this can be upwards of 70 degrees Celsius) and for this reason there is normally a heat sink and fan attached to the processor to cool it. Sometimes in more advanced machines water cooling is used.

Heatsink and fan

inside a computer- heatsinkA heat-sink is something that cools a device by taking heat away from it, in this case a processor. The idea is that the heat is pulled from the processor via the heatsink and blown out of the case via a rear fan. You will then likely have a fan in the case that is blowing cold air INTO the case. You can get a heat-sink without a fan called a passive heat-sink but most modern processors require a fan to be attached to the heat-sink.

Heatsinks also have a paste called thermal compound or thermal paste that sits between the processor and the heatsink. Thermal paste is a very high heat conductive and sits in between the two to get better conduction as it fills in microscopic imperfections on the heatsink.

RAM/ Memory

Memory or RAM (Random Access memory) stores data that is to be processed by the CPU (processor). RAM is volatile which means that unlike your hard drive it needs constant power to keep its data. If you turn the computer off the data is lost. Having more memory can greatly increase the speed of your computer. It is not unusual to see computers now with memory of 8GB. RAM is expandable which means it is a part you can upgrade in your desktop or laptop computer. A good place to buy RAM is crucial memory who have a tool to tell you which memory is compatible with your computer.memory

Hard Drive

1tbdriveThe hard drive is one of the most important parts of a computer as it stores all your data, programs and settings as well as the operating system for the computer. Unlike RAM it is non-volatile memory which means when the power is turned off your data remains. Hard drives vary in size from about 40GB in very old machines to over 8TB which is over 8000GB! (consumer products). Most hard drives now have Sata connections but some of the older hard drives had an IDE cable. Classic hard drives are mechanical and consist of one or more platters to which data is written using a magnetic head.

Lately due to a drop in price SSD drives are now becoming the more popular option due to their speed. An SSD drive uses non-volatile memory much like a USB flash drive to store data meaning the data can be accessed much faster than on a classic hard drive. It also has no moving parts so is quieter and consumes less power. Although prices have dropped significantly in recent years and they are worth the investment they are still more expensive than standard hard drives especially at larger capacity’s. As an example a 1TB SSD will likely cost around £300 while a 1TB standard drive can be picked up for around £45.

PSU (Power Supply Unit)

psuAs the name suggests this is the part of a computer that supplies the power to the other parts of a computer. It is very important that the power supply is matched to the requirements of the hardware that is installed. For example a custom-built gaming machine would most likely not work correctly or at all with a power supply under 500 Watts. It is also important that the power supply has the right connectors and enough of them to power everything you want it to (sata power cables, molex power cables).

It is possible to now but power supplies that are modular meaning you can add and remove different connectors when you need them.

parts of a computer - Graphics cardGraphics Card (GPU, Video Card, Video Adapter)

This is usually an expansion card that provides images to your display. Most motherboards do provide some form of basic graphics embedded into the motherboard.  If the computer is used for gaming or video editing it is common to have a more powerful expansion card installed. Depending on the power of these graphics card they may come with their own heat-sink and fans to keep them cool.

Most modern graphics cards now come with HDMI, VGA or DVI Slots.


DVD dirveDVD/CD Drive

This is the place where DVDs and CD’s are inserted and is caused an optical drive. This part of the computer usually has 2 connections, a power connection and a data connection. The data connection is usually a SATA connection but can be an IDE connection in older models. Most modern drives now have the ability to burn CD’s and DVDs as standard now.

What Are The Different Parts Of A Computer?