A "player campaign" refers to a game mode or a series of levels designed for a single player to complete, where they can follow a storyline or achieve certain objectives on their own, without the involvement of other players. Full definition
You can discover a world at war in single player campaign mode or play epic team - based multiplayer battles. (jelly.deals)
Although there's a massive single player campaign in the game it's the competitive multiplayer where the game really comes to life and is the most fun to play. (nintendo-insider.com)
Not big on always requiring a connection for single player campaign mode. (toucharcade.com)