Builders· 4-bit
Binary is counting with two digits. Each place is worth double the one to its right.
You count with ten digits, 0 to 9, probably because you have ten fingers. When you run out of digits you add a new place: after 9 comes 10. Each place is worth ten times the one to its right: ones, tens, hundreds.
A computer has only two "fingers": off and on, 0 and 1. So it runs out of digits much sooner, and each place is worth only twice the one to its right: 1, 2, 4, 8, 16, 32, 64, 128. This is the binary system.