The operators serve to perform operations in the same way as functions do, but using operators, your code is more compact and legible.
Operators can be arithmetic, relational and logical. The arithmetic operators can be used in all expressions, not only the logical ones. The relational and logical operators serve to create expressions with resulting boolean value.
All operators can be grouped into four categories:
Arithmetic Operators (+ - * / % ++ --)
Relational Operators (> >= == <= < != ~= ?=)
Logical Operators (&& || ! == !=)
Assignment Operator (= += -= *= /= %=)