Strongholds (Halo Wars)
From Halopedia, the Halo wiki
In Strongholds, players start with unlimited Supplies and Power, with the only limit on army building being a hard population cap. Unlike other modes such as Deathmatch, Strongholds does not focus on base-building but instead on capturing and holding predesignated Stronghold sites across the map. Every stronghold controlled increases the controlling team's population cap by 5.
To help with the gamemode's rapid pace, the time limit is set to 15 minutes and armies and structures are built extremely quickly. In addition, tech levels are unlocked over time, keeping all players on an even footing of unit upgrades. The game victors are the team that controls the most strongholds at the end of the match,
The eponymous Strongholds appear on the map as predefined minibase construction sites that, when built upon, will construct a UNSC or Banished Stronghold. The UNSC Stronghold comes with a UNSC Minibase with a Barracks, Garage and Airpad automatically attached, while the Banished Stronghold is a Banished Minibase that comes with a Raid Camp, Foundry and Apex attached. This allows the controlling player to quickly begin manufacturing units. When called in, the base and buildings are dropped from orbit near-instantly.