Goodness. If you're that much of a n00b, you'd better go and read up books on basic computing...
A computer is basically made of a calculator, a storage area, and inputs and outputs. We'll study all three in separate chapters...
I. The calculator
intro.
You have a generic one, usually named the Central Processing Unit (CPU): this is your Athlon or Pentium.
a. The CPU is geared towards generic operations and is very versatile. It's power is (VERY ROUGHLY) measured through its frequency, the number of virtual and/or real processing units and cores, and the instruction lenghts it can process.
In short, how many cycles per second, how many operations per cycle, and the operation lenght a CPU can process allow you to measure how powerful it is.
b. Overclock (O/C)
Overclocking your CPU means that you force it to frequencies higher than the one the CPU maker recommends: it usually voids its warranty and requires very careful tinkering with many precise settings for it to be workable and effective. Some CPU models are very easy to overclock, and amongst those, some samples will go higher than others.
II. The storage area
intro.
You have 2 main sorts, one which is very fast but volatile (it empties every time the power is down) and one which is much slower but stays after power down.
a. the volatile RAM
The volatile system storage area is your system RAM; the more RAM you have, the more data the CPU can access rapidly to process, and it empties everytime you turn off your system.
b. the nonvolatile RAM
The non-volatile is basically your hard disk, but you can count CDs, DVDs, USB keys and such among those too. It is used to host files which will be loaded in system RAM when they are required. This loading time is the biggest slowdown for a computer.
c. virtual RAM
Virtual RAM is referring to using a big, single file on the hard disk to unload data from system RAM that is temporarily unused, so that more used data can remain in the faster system RAM. Its access is slow (it is referred to as 'swap'), and reducing swapping is done through increasing the amount of system RAM and/or reducing the amount of used RAM (by closing down unnecessary softwares, such as system tray helpers, background tasks, and other useless wizards).
III.inputs and outputs (I/O)
Basically, you use the keyboard and mouse to 'talk' to the computer, and the screen, sound card and/or printer 'answer'. Network/Internet connections can be used either as I/O or as storage.
IV. Dedicated RAM
For more precise tasks such as 3D gaming and 3D positional audio, there are what are called 'accelerators' or 'coprocessors': a Graphics Processing Unit (GPU) for example, will use some basic instructions provided by the CPU ('draw a triangle with 3 textures layered on it on coords x1y1,x2y2,x3y3 with shading effect 25 and 302') to render each dot on screen.
Due to the large amount of data required, most GPUs have dedicated RAM: either a share of your system RAM (for budget, slow solutions), or some dedicated, very high speed RAM.