Computer understands colour and numbers and alphabets by bimary code. Computers have two electrocity. They are on and off. If the computer is working with electrocity it means it knows only off and on (yes and no). Everytime we had more switches, we have more possibilities. Every switch will not do only one job or work, it has alot of meanings. Everything computer understands is a bimary. In bimary we have only one (1) and zero (0). For example if we need to write three (3), we go on two (2) and put one because we only need one two there and in one (1) we put one , so two plus one is equal to three (2+1=3). This is how a computer works and understands everything. Every piece of information is a bit. A bit will equal to A (switch A in keyboard), it is bimary code. Eight bits is byte. A CD-ROM has 700 megabits.