In modern fencing, you move backwards and forwards on a strip. In movie fencing, you move wherever you damned well please.
Fencing strips. They're 14 meters long and about one-and-a-half meters wide. And they don't exist in movies. Onscreen, it's typical to see two fencers - rather, two people in fencing uniforms - swordfighting all around the room (or whatever environment they happen to be in). Usually done for Rule of Cool, in an actual fencing match, leaving the strip during a bout results in a penalty or a point for your opponent.