Calculating word length refers to the number of binary digits it can handle at a time. The speed at which a computer processes data is naturally related to the number of bits it can process at a time and the operation speed. If the word length of one computer is twice as long as that of another computer, even if the two computers have the same speed, the former can do twice as much work as the latter in the same time. Computers are made up of binary. A byte is 8 bits long. Because it is a binary octet, the range it can represent is 0000000 ~11111. And binary1111is equivalent to decimal 255, so the value range of an octet in binary is 0~255.