Limit of a function

When a number is really big or really small, a function can "reach a limit" - or an end. So, imagine you built a really tall tower out of blocks - the blocks are the numbers in your function. As the tower gets taller and taller, eventually it will reach the highest point it can - that's the limit. That's what happens in a function too. As the numbers get more and more, the function will eventually reach a maximum number that it can get to - that's the limit.