There is quite a bit of computer hardware.... any particular pieces? Or a certain number of them?
The Monitor - They display what is going on in your computer. The monitor has three main parts of importance to users: size, refresh rate, and resolution. The size is measured diagonally and is how large of an area the viewable screen is. The refresh rate is how often the picture is refreshed on the screen. A high resolution has sharp and detailed images.
Hard Drive - The hard drive stores most of the information of a computer. It holds the programs that have been installed, as well as files that have been saved. The hard drive is a round disc that stores information in a series of 1s and 0s.
I hope this helps!