In the context of computer science the term operator has two different meanings. The first, and relatively trivial meaning, refers to the person whose responsibility it is to ensure that a computer or computer system is running properly. Tasks associated with the operator's position include preparing storage media and making backup copies of files.

The second meaning of operator is a symbol representative of a specific action. Many operators exist in the myriad of available programs and programming languages. For example, a plus sign is an operator, which represents addition. The other basic mathematical operators are the subtraction sign and the multiplication and division signs. For example, in the expression 5 + x, the + is the operator. The 5 and the x, the objects that are being manipulated, are called operands.

Mathematical operators are relatively simple in their actions. Other operators allow the manipulation of numbers and text in more complicated ways. A Boolean operator is one example. Boolean operators allow for a TRUE or FALSE determination of information. One type of Boolean operator is known as an OR operator. It can also be called an inclusive OR. This operator returns a value of TRUE if either or both of its operands is TRUE. Another type of operator, the exclusive OR, returns a TRUE value only when one of the operands is TRUE. If both operands have the same value, an exclusive OR does not return a TRUE value. Put another way, an inclusive OR can be "this, that, or both", while an exclusive OR means "this or that, but not both."

Another operator is called a relational operator. This type of operator allows one value to be compared to another. Hence, this operator is also known as a comparison operator. An example of a relational operator is the expression x > 10 (x is greater than 10). This expression will have a value of TRUE if the variable x is greater than 10. If x is less than 10, the expression will be FALSE.

Operators are essential for the construction of expressions, and so are a vital component of programs and programming languages.