It is part of the Team Objective category. In this mode, the main objective is to destroy the enemy team's generator while at the same time ensuring the safety of your own from enemy attacks. Generators can be damaged with any weapon or attack that the player can make, both structures have 100 of Generator-HP (different from player HP) and the more damage they take, the damaged they appear. The generators' shields will drop in an alternating fashion, meaning that while one generator is protected, the other one is not, making both teams migrate between the two structures to attack or protect them. Both generators HPs are displayed on the player's HUD represented with a full bar, the more damage is dealt, the smaller the bar gets.
Like most team game modes, three Control Points can be found in the match, Health - Speed - Damage, and can be captured by standing near them; these pillars grant stat boosts for the members of team that captures them. Capturing and securing these can take some time and are not mandatory to win the match, but definitely aid the team that controls them.
If neither team's generator is destroyed within the time limit, the team with the most intact generator is declared the winner.