system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Alternating Current. Do electrons keep going forwards and backwards in a wire when AC is flowing?
gpt
Picture a tube of tennis balls, with both ends cut off. 

Direct current is when you take a ball and push it in one end, causing one at the other end to pop out. 

Alternating current is when you push a ball in one end and it pops one out the other, then push one in the other end and pop one out the former. 

Over time, for constant frequency AC, the total change in distance for any ball inside the tube is 0. 

Does that answer your question?