Is your computer running slow? Do you think that notebook of yours could use a quick boost in performance? When it comes down to what makes a computer fast, there are about 3 or 4 key factors you can look at to really make a change in your system's performance from a hardware perspective, but there are also a number of secondary factors to consider, too. If you're ready to give your computer a good hard look, and make a few changes for a huge difference in performance, then read on ahead for a guide on the basics of a computer, where to look, and what to consider!

Computers are very simple machines, really. When it comes down to the basics of what makes a useful complete system, we can narrow it down to three parts that are the key necessities: the processor (central processing unit, or CPU), the memory (random-access memory, or RAM), and the hard-drive. Even in some cases a hard-drive isn't necessary, but something else must take its place, like an optical drive complete with some operating system (OS) on the inserted disc. Either way, the hard-drive or other drive contain some sort of operating system with which the processor works with. The OS is like a set of rules, instructions, or something of a map for the computer system to follow and abide to; if some process in the system were to stray from the operating system's rules, that's when we experience things like the infamous blue-screen-of-death or minor software crashes. Some operating systems perform better, faster than others, and that usually depends on how big of a workload does the OS give the computer. For instance, some OS' are so small, simple, and nimble (like Puppy Linux), but they aren't as capable and outfitted to do everything that bigger systems can do (like Windows Vista, or Apple OS X), which trade off speed for other features.

Of all parts of the computer, the processor does all the work, organized into packets from the operating system (via the hard-drive), for every single little thing you do on your computer. Move the mouse? There's a work packet sent to the CPU. Open Safari or Firefox? You just loaded the CPU with more work. Nearly everything you do ends up going through the CPU. Now, where does the RAM come in, you ask. The speed of even the most modern hard-drives is still way too slow for a computer to rely on alone, so every system that we use today utilizes random-access memory (RAM) which make those work packets move from the hard-drive to the CPU at an incredible rate of speed.
Imagine this: you're working in your garage and building a birdhouse. You, the builder, are like the CPU of the computer, doing all the work to make this product to set outside your window. Everything you need is in your toolbox (in this story, the hard-drive) on the floor, hidden under piles of other useless equipment and hardware; but, your workbench (the RAM) is right there in front of you, open and vacant. When you put all the stuff you need (like the hammer, nails, wood, etc) on the workbench, it's all within arms reach and easily accessible at any time. Picking up items and putting them down on the bench is seconds and sometimes minutes faster than having to stop and go to your toolbox for the next nail or piece of wood. So, in the big picture: the processor does all the work, the hard-drive contains all the work for it to do, and the random-access memory is like a high-speed conveyor belt for sending the work back and forth from hard-drive to the processor.

The only thing that may differ from those situations, is if your computer is a more complex system than as described above, which means it may include something like a video card to process all the visuals you see using your computer, or maybe a sound card to re-direct some of the work from the CPU to a secondary processor, located on the card.

When it all comes down to it, if you're looking for the easiest, cheapest, and best upgrade that your computer could use, then look first at its RAM. Your priorities should be to increase the capacity of your random-access memory, then maybe the speed of the memory or the processor. RAM is reasonably affordable these days, and you can use web services like Crucial.com to help you select the right kind of memory for your specific system!