I often see phrases like "two-frame punish" when watching Super Smash Bros 4 tournaments. I often see it when people are edge guarding, and it some how prevents players from grabbing the edge. What does this mean?
As pointed out by @Nelson, I did some quick research and found the answer from Smashpedia:
The Two Frame Punish is a mechanic and technique in Super Smash Bros. for Nintendo 3DS and Wii U, in which an edge-guarder's attack is timed in order to punish the opponent on the two frames of vulnerability that occur at the beginning of a ledge grab animation.