Modes in PvE:
Assault- capture enemy positions in the allotted time
Destruction – to destroy a specific military target
Escape – move between two points under heavy enemy fire in the allotted time
Defend – hold a location or multiple locations against an assault for a given time period
Survival – waves of enemies and must be defeated before a timer runs out or the team is defeated.
World of Tanks offers other PvP game modes including pre-formed teams fighting in Clan Wars, Strongholds, and tournaments. Armored Warfare will have some type of clan system and different PvP battle modes, but those details have not yet been released.