Base 2 refers to binary numbers- a system that only uses 1's and 0's. It is used predominantly for computers.
Base 8 refers to Octal numbers- 0, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17 (consists of 16 numbers)
Base 10 refers to Denary/ Decimal numbers- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (consists of 0-9 numbers)
Base 16 is Hexadecimal numbers- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F (contains 16 numbers as well, but utilizes alphabets to eliminate use of 2-digit numbers, thus making it easier to memorize and use). It is predominantly used to code colors.
(Lucas)