Binary number

Binary is a base-2 positional number system that represents values using only two digits, 0 and 1. Each position is a power of two, and each digit is a bit. Computers use binary because the two states map directly onto on/off electrical signals. Groups of 8 bits form a byte, and binary converts cleanly to hexadecimal (4 bits per hex digit).

Example: Binary 1011 = 8 + 0 + 2 + 1 = 11 in decimal.