What does it mean for a function to return a value?and where does it return?

Answer 1

You write a function either asking it to print something on your behalf and not return anything.
Or if you say to the function that I'm giving you a value, so kindly process it and give me the updated result then it can do that as well by returning something.

It returns to where you have called it inside the main method.

Answer 2

here is an analogy. think of an restaurant you are the waiter.

when you recieve an order, you immidiately write them down and give it to the kitchen (pass an argument). they cook for a while and give the food back to you (return the value) to be served.

if i write it in code.

function kitchen(order)
//cook the food written in the order
return food

function main()
//order recieve
order = new Order ('burrito')
//send the order to kitchen
served_food = kitchen(order)
// ^ take the food when done as served_food