What is the return keyword used for?

I seriously do not get it. I know that functions is a way to store your code such that you can call it when you need to like when an event was triggered. I understand what arguments/parameters are and what they are useful for. However It is this return.. What is it? Is this what it means? "point of returning is so that you can have a function that performs a calculation or a set of instructions for you and then returns the value that it calculated back to a variable.?" When I think of the word "return"I think of a person going to a place and then coming back. People also explained that return is a keyword to return to the function caller. What is the function caller? and return.