The binary 0 can be created with 0V voltage, the binary 1 with +5V voltage. It is made up of eight binary digits (bits).Computers are designed to use 8-bit groups called byte. It is also the common unit of computer storage from desktop computer to mainframe. These units store data of one character (e.g. an ASCII code).using the 8 switches on and off 265 combinations can be generated (28 = 256). So a byte can hold values from 0 to 256. While working computers and networks it is very important to understand the definition of the byte.