What does an operator do in programming?

In programming, an operator is essential because it performs operations on variables or values. This includes a range of functions, such as arithmetic operations (like addition or multiplication), comparison operations (such as greater than or equal to), and logical operations (including AND, OR, and NOT). By using operators, programmers can manipulate data, perform calculations, and control the flow of a program based on certain conditions.

The other options describe different aspects of programming: defining return types is related to functions, creating new variables pertains to variable declaration, and looping through instructions refers to control structures like loops. These concepts are important, but they do not encapsulate the primary role of an operator in programming, which is specifically to carry out operations on data.