Pokemon battle games are unlicensed online freeware that let players select and design Pokemon stats and move sets within agreed upon parameters before deploying those Pokemon in battle against other Internet users. These games differ and encompass genres as diverse as role-playing games played in-browser and multiplayer battle engines with no story component but robust competitor matching and ranking systems.
Pokemon Battle Arena is a matchmaking competitive game where hardcore Pokemon trainers can try out builds and teams in various formats. They are matched with players who desire to compete under similar rule sets and constraints and can then fight one another. Victors accumulate ranking on the site leader boards if they are registered.
Pokemon Battle Quest is a role-playing game that is in some respects similar to the traditional Pokemon game system. It lets a player character explore an open world bounded by ability limitations connected to player level. It also lets that character raise Pokemon and develop their powers, but it has a unique story element and other features that set it apart.
Pokemon battle games fall under the heading of community features and fan fiction. They are not part of the canonical series of Pokemon games but rather serve as outlets for alternate developments of the property.