Not all computers are created equal
Computers are built from components which each have a separate functions but work together.
The Processor (CPU) is the ‘brain’ of your computer, the thing that carries out the tasks you give it. Better CPUs can perform more tasks at once, and perform them faster.
Not everyone actually takes advantage of their processor’s full speed, so the high-end models are only really crucial if you’re performing intensive tasks like video editing, video conversion, compiling code, or (to a lesser extent) gaming. It’s also one of the most expensive parts of a machine, so if you aren’t performing these types of tasks, you definitely don’t need to worry about buying the latest and greatest.
The motherboard connects all the other components to one another, and is the physical base upon which you build everything else. It contains a lot of your machine’s core features, like the number of USB ports, the number of expansion cards you can put in (such as video, sound, and Wi-Fi), and also partially determines how big your computer will be. Which motherboard you pick will depend on what you want to do with your computer.
The case holds all of your computer’s parts together. For the most part, a case is less about features that affect how your computer runs and more about features that affect you and your home. How quiet it is, how large it is, and of course, how it looks in your home or office.
RAM, or Random Access Memory, is like your computer’s short-term memory. It stores data your computer needs quick access to help your programs run faster, and help you run more programs at one time. Thus, if you run a lot of programs at once, you’ll want a computer with more RAM. If you use virtual machines, you’ll want even more RAM, since it has to run its own programs in addition to yours.
The Graphics Card
The Graphics card, or GPU, is a processor specifically designed to handle graphics. It’s what you hook your monitor up to, and it’s what draws your desktop and your windows on the screen. Some motherboards come with a GPU already integrated, which is enough to manage your desktop, but usually not enough for playing 3D games or high grade graphic design, for those, you’ll need a dedicated graphics card.
The Hard Drive(s)
Your hard drive, not to be confused with memory (RAM), stores all of your data, ranging from your operating system to your documents, music, and movies. If the RAM is your computer’s short-term memory, your hard drive is the long-term memory. It stores the things you want to keep around for a while. The kind of hard drive you choose will be determined mainly by how much data you need to store and the programs you need to load on your hard drive, but certain kinds of hard drives (like solid state drives) can also affect your computer’s speed.
The Optical Drive
An optical drive, more commonly known as a CD or DVD drive, is what you’ll use to read CDs, DVDs, and even Blu-Ray discs. Not everyone needs an optical drive in their computer these days, but since you can buy one for about $30, there’s little reason not to have one.
The Power Supply
The power supply directs electricity to the other components in your machine. Generally speaking, if you have a high performance computer with a fast processor, a graphics card, and a few hard drives, you’ll need a higher wattage power supply than you would if you were building a low-end PC. This is probably the last component you’ll shop for, once you’ve nailed down your other parts and how much electricity they’ll require.
Other Parts to Consider
While these are the main parts almost every computer has, you probably have other needs. For example, if you’re going to use Wi-Fi to access the internet instead of wired Ethernet, you may need to buy a Wi-Fi card. If you take a lot of photos, it’s probably worth getting an internal SD card reader for easily loading your photos onto your computer. If you have any Bluetooth peripherals, you might consider an internal Bluetooth card, and if you video chat with friends, you’ll want to pick up a webcam. You will also need a monitor, keyboard, mouse and speakers.