A return statement is a programming construct used in functions to send a value back to the part of the program that called the function. When a function executes a return statement, it stops running and provides the specified value, which can then be used for further calculations or operations. This allows for better organization and reuse of code. In many programming languages, such as Python, Java, and C++, the return statement can also indicate the end of a function's execution. It can return various data types, including numbers, strings, or even complex objects, depending on the function's design and purpose.