A condition is a comparison. This phrase encompasses the essence of what is a condition. A simple condition is made of three elements:
Values may be of any type (numericals, character strings or containers) and may be expressed explicitly as constants or implicitly as expressions to be evaluated. In order for a comparison to make sense, compared values must be of the same type or of comparable types.
The comparison operator in a simple condition is called a relational operator. These operators are used to compare the magnitude of two values.
A simple condition can also be a type validation, which are tests used to verify the type of a value. The tested value may it be a constant or obtained from an expression.
Furthermore, simple conditions may be grouped together into a compound condition using logical operators.