ASCII
ASCII uses 7 binary digits (bits) to represent characters. The bits 1000001 (65 in normal base-10 numbers) represent the upper-case letter A, 1000010 represents B, 1000011 represents C, and so on. Using the table below, you can look up a number in the Decimal column and see the character it represents in the Char column. Programmers often use hexadecimal (base-16 numbers), and you can look that up in the Hex column.