4-Port ADSL Router User Manual

Appendix B
174
Bits and bytes
Computers handle binary numbers by grouping them into units
of distinct sizes. The smallest unit is called a bit, and the most
commonly used unit is called a byte.
Definition (bit and byte):
A bit is a single binary digit, i.e., 0 or 1. A byte is a
group of eight consecutive bits (the number of bits
can vary with computers, but is almost always eight),
e.g., 11011001. The value of a byte ranges from 0
(00000000) to 255 (11111111).
The following shows the values of the eight digits in a byte along
with a sample value:
128's
64's 32's 16's 8's 4's 2's 1's
10101101
The decimal value of this byte is 173 (128 + 32 + 8 + 4 + 1 = 173).