For most people what’s on the inside of their computer isn’t something they think about. If you ever do look inside your computer it may appear quite baffling but it’s not really as complicated as it looks. After all, it’s only a machine made up of individual parts. Now, although these parts are very complicated indeed just think of them as jigsaw pieces each connected in the right way to make up the whole.
The first piece to know about is called the CPU which stands for “Central Processing Unit”. This is the brain of the computer. The CPU is plugged in to a large printed circuit board called the Motherboard complete with lots of electronic circuits already soldered in place. These two, the CPU and Motherboard, are the actual computer. Without these working properly your computer is nothing more than a large door-stop.
Everything else the computer needs in order to make it actually useful to you is plugged in or connected to the Motherboard in some way. So, of course, there is the Power Supply Unit (PSU). There’ll be power connections to the Motherboard and other devices. Following these power connections you’ll come to a DVD drive and the hard disk drive. For full-sized home computers the hard drive will be a 3.5 inch drive held in place by four screws in a special bay on the computer case. Both the DVD drive and the hard drive will have a cable that plugs in to the Motherboard. The cable may be a wide ribbon style cable and the plug have about 24 sockets or it may be a narrow single cable the plug having one socket. The drive with a ribbon cable would be an IDE drive and the drive with the narrow cable a SATA drive. All new computers use SATA for the hard drive though some still use IDE (ribbon) for the DVD drive.
The hard drive is where all the software that makes the computer work is located and also where all your files are located. It’s not unknown for a hard drive to break down and for people to lose their files – all their photographs, videos and music, so it’s very important to make a copy, or backup, of these files. A simple way to keep a backup copy of all your files is to use a 1TB External Hard Drive which is large enough to store most people's data many times over.
The computer will not be much use to you if you can’t see what’s happening so there’s a unit plugged in to the Motherboard called the “Graphic Card”. This takes all the video signals from the CPU and processes them for display on your monitor. Some motherboards have the graphics unit built in so you may not see a separate card for the graphics. Another part of your computer which is frequently built in to the Motherboard is the sound card although some more expensive computers will have a separate card that plugs in to the motherboard, especially those with 5.1 or 7.1 surround sound.
The motherboard also contains the RAM or Random Access Memory. This is the working memory that the computer uses when it is switched on. Any data in RAM is lost when you switch off the computer that’s why the computer uses a hard drive. Data is transferred to and from the hard drive to RAM continually so it’s always a good idea to have lots of RAM so data doesn’t have to go back and fore so much.
The motherboard will have integrated sockets or “ports” that allow outside devices or “peripherals” to be connected to the computer. There will be USB ports for devices such as keyboard, mouse, printer and camera, a network port to connect to your broadband Internet service, a video port to connect your monitor, headphone or speaker sockets and one for a microphone. Older computers may have other ports such as a parallel port (usually for a printer), serial port (some older cameras used this) and modem port (for dial-up Internet access).
All together these individual units make up the computer. Each one can be disconnected from the motherboard and replaced if something goes wrong with one of them or, more commonly, to improve the performance of the computer.