Maps are the areas in which battles take place. There are a variety of different shapes and sizes to capture many different opportunities, advantages and strategies. From the map selection you can also select a randomly generated map, or a random map.
Depending on what map you choose, different xp modifiers may apply. The above examples give 1.2xp each, while pre-set maps can give values between x1.1 and x0.8 XP for the match (Shown in bottom right corner of a map in the selection screen). If a map has no value attached, that means it has the default XP multiplier (x1.0).