An "overload" means that the amount has crossed some kind of line or threshold. (Usually this is a bad thing, for example with electrical circuits) A "surge" is a sudden increase. It is possible to have a surge, or many surges, without an overload. For example: "There were many electrical surges during the storm, but the system was not overloaded." Good luck!

Hi Chris, A "surge" is a sudden, large increase in something. "Overload" usually means that the increase that happened is too much for the person/system/structure that has to handle it. An overload can come from a sudden surge, or it could also come from a more gradual increase that never stops. Hope that helps!