Binary

Binary (or base-2) is a representation of numbers using only 2 symbols: ones and zeros.

2^7	2^6	2^5	2^4	2^3	2^2	2^1	2^0
128	64	32	16	8	4	2	1

Using the above table, you can represent any number in Binary. For example 201:

128	64	32	16	8	4	2	1
1	1	0	0	1	0	0	1

128 + 64 + 8 + 1 = 201