In programming, a value written exactly as it's meant to be interpreted. In contrast, a variable is a name that can represent different values during the execution of the program. And a constant is a name that represents the same value throughout a program. But a literal is not a name -- it is the value itself.
A literal can be a number, a character, or a string. For example, in the expression,
x = 3
x is a variable, and 3 is a literal.