A character contains any alphabet, digit or special symbol to represent information. The set or character which is valid in C program is called character set. The set includes some graphic characters. Graphic characters contain alphabets, digits and some special symbols. C language uses case letters (a to z), the digit (0 to 9) and certain special characters like constants, variables, operators etc. and some special symbols:- $, <, >, <=, =, !, # etc.

Non graphical character sets contain white spaces these are also called escape sequences.