When building a computer, it is essential to get all the parts correct as it is like a jigsaw, you cannot force one part to go with another. RAM is a main part of a computer as it stores the temporary data on your computer, e.g. if your writing a word document and the power cuts out without you saving your work, the temporary data is wiped clean and you will have to start all over again. RAM is like a smaller hard drive that only stores data temporarily. The more RAM you have the more temporary data can be stored as some games require you have a certain amount so it can store temporary data for the game to function correctly.
RAM is good in masses of amounts but can cost a lot. These days if you want about 2GB RAM it will cost you around 50.00GBP you can probably find cheaper by searching the Internet.
CD, DVD Drives? These are essential to any computer as mainly DVDs are used to store masses of data like, programs, games and so on. But as always these drives might need to be changed as technology improves, so does new ways of storing data like Blu-ray (Blu-ray can store masses of data but Blu-ray drives can cost a lot to be put in your computer). DVD drives can be bought external so there is no need to have it built in, even though it is better have it built in, instead of having more wires.
Overall a DVD Drive is a must have. Graphic cards are getting bigger now as games require more realistic graphics so does the strain on your graphic cards performance. If your card is not good enough you might lose some of the feeling for the game or it might be "blocky" (not well textured and is not well detailed). If you're trying to make a gaming PC, then a graphic card is a needed component.
Motherboard, as you can probably tell, is the main part of the computer. This is where the other parts of the computer connect and make the computer function correctly. There are 2 main companies that build motherboards AMD and Intel both have very good motherboards and it really what specifications you want your computer to have that is the deciding choice over these companies. Hard drives are the part that stores are data you want to have when you boot up your computer they are like RAM but it is always there unless you delete it from your hard drive. You can get external or internal hard drives and you must have at least one of these or you most likely won't be able to boot up your computer. You can get fairly keep ones or fairly expensive but big ones.
It's again dependent on what you want your computer to do. If you are requiring your computer for gaming then you will need a fairly big hard drive to save all the games on your computer about 250GB+ should cover you if you play the newest games. If you use your computer for 1 hour a day then you won't need a massive hard drive. As you probably won't play games and will only store text files or pictures on it.
You would probably need a 50-200GB Hard drive If you want computer that can run nearly any program smoothly even some that will come out in the future, then you will require buying a lot of RAM, a big hard drive and a fast processor. As technology moves on, so will the need for a faster computer. So, you could be saving in the long run by buying the expensive equipment now. On the other hand it could get cheaper in the next month or too.
IF you are just going to use your computer to check the e-mail's or just to put some pictures on then you will not need a extremely fast computer, maybe just a slightly big hard drive to store all them pictures on and the programs to edit or burn the photos to a disk.
Darren writes on topics such as How to Build a Computer, Build a Computer, and Build a Custom PC.