A Map is the location where a battle takes place in the Advance Wars Games. A Map has many features, mainly Terrain, though it may also have pre deployed Units or special features for that battle (Mainly on Campaign). Maps can be broken down into several different kinds:
Single player Maps which can be played outside of Campaign, on certain games they may give currency or other rewards for clearing them. Although players start off with some Battle Maps, they will generally need to purchase more with War Funds.
Maps which can be played on with other players and/or computers, there are no rewards other than the fun of playing against non computers.
Pre Deployed Maps
The term given to a Map which already has Units placed on it. This can be a very wide term ranging from Maps with no other ways whatsoever to get Units, to Maps where there are Productive Buildings as well as Units already there.
Maps which can be played online against other players, via Nintendo Wi Fi.