Expressions : An expression is a combination of variables, constants and operators written according to the syntax of the programming language. In the C programming language every expression evaluates to a value i.e., every expression results in some value of a certain type that can be assigned to a variable. Every computer language specifies how operators are evaluated in a given expression. An expression may contain
Arithmetic operators: Operators, which are used to perform arithmetic operations such as addition, subtraction, multiplication, division etc.
Logical Operators: Operators under this category are AND, OR, NOT.
Relational Operators : >,<,=, not = ,<=, >= these are the relational operators.