The binary system on computers uses combinations of 0s and 1s.
In everyday life, we use numbers based on combinations of the digits between 0 and 9. This counting system is known as decimal, denary or base 10.
A number base indicates how many digits are available within a numerical system. Denary is known as base 10 because there are ten choices of digits between 0 and 9. For binary numbers there are only two possible digits available: 0 or 1. The binary system is also known as base 2.
All denary numbers have a binary equivalent and it is possible to convert between denary and binary.