In this article I give a high level overview of all the major components of a computer – the computer hardware. This information is useful for anyone who wants to be able to repair or upgrade their computer, or just wants to have a basic understanding of how a computer works.
The computer is housed inside of what’s called the computer case. The computer case is the metallic box that surrounds the computer. It’s there to protect the computer and to hold the components in place.
The power supply is the box with lots of wires coming out of it. It takes the electricity that comes out of the wall outlet and converts it into electricity that each of the internal components can use.
The motherboard is a big circuit board that connects all the internal components together. It gives the internal components a way to communicate with each other. It also provides some common functionality that is basic to all computers – audio, network, modem, sometimes video, and a few other things. These additional devices that come as part of the motherboard are called integrated devices.
The motherboard also has slots that other device cards can plug into and provide extended functionality to the computer. Some of the more common cards are wireless cards, USB extension cards (provide additional USB ports), and even video cards – which I talk about below.
The CPU (Core Processing Unit), also known as the processor, is the main logic component of the computer. It decides what to do, what to load, which other device to activate, etc. It’s kind of like the center of the brain.
The processor tends to get extremely hot, so it’s always covered by a heat sink (metal thing with fins) and a fan. The processor itself looks like a standard chip.
The hard drive is the long-term memory of the computer. The long-term memory is slower and much bigger than the short-term memory, specifically made for storage of data. Read the section on main memory for information on short-term vs. long-term memory.
Also known as primary memory, RAM, or just memory, is the short-term memory component of the computer. Short-term memory is much, much faster than long term memory, but is also much, much smaller in size.
Main memory is not used for storage of data over the long term. Unlike the hard drive, main memory has to have power to keep information. Once the computer is turned off, the main memory is cleared out. Instead main memory is used for fast data access. Once the computer knows what data you’ll be working with, it loads it up in one big chunk into main memory, and works with it there. For example, when you run application xyz, your computer loads up lots of the common data that the application needs into memory, from then on it works with it in the much faster main memory. Then once you want to save your changes, the computer writes that data out to the hard drive for long term storage.
The video card handles the display of images and 2D/3D graphics calculations. Often the video card comes integrated into the motherboard. But integrated video cards are somewhat weak. The powerful video cards, needed to run modern games and other graphically intensive applications, come as standalone cards. They are big circuit boards with their own processor (GPU) and memory. They even have fans and heat sinks. They are kind of like separate computers inside of the computer.
These are standard devices that read and sometimes write CDs and DVDs.