In programming, a function is a self-contained block of code designed to perform a specific task. Functions generally take inputs, known as arguments, and return outputs, known as return values.

When you define a function, you specify a set of arguments that the function needs to operate. These arguments act as placeholders for the values you pass to the function when you call it. For instance, if you have a function that calculates the sum of two numbers, you would pass these two numbers as arguments to the function.

Once the function processes these arguments, it performs the defined operations—such as addition, subtraction, or any other logic—and then produces a result. This result is returned by the function as a return value. The return value is the outcome of the function’s operation, which can be used further in your program or displayed to the user.