An expression is a programming language construct that evaluates to some quantity.

For example, b + c is an expression that evaluates to the sum of b plus c. If b = 2 and c = 3, expression b + c evaluates to 5 (2 + 3 = 5).

Literal

A literal is an expression that literally declares its value.

For example, 5 is an expression that evaluates to 5. Because the expression's value is literally declared, it is a literal.