The Archangel-Class Planetary Assault Landing Ships are the largest starships dedicated to the Terran Protectorate Colonial Marine Corps. Each ship is capable of carrying an entire marine regiment, and every marine regiment is assigned to one particular home ship. While most operations involve the use of the smaller Titan-class transports, capable of carrying a company of marines, these vessels are held back for massive, long-term operations, like planetary assault and liberation of major worlds. As many as 200 regiments may be involved in such an operation, each arriving in one of thes nearly 3,000 foot-long vessels. They not only carry all of the equipment, personnel and even administrative facilities for each regiment, but they also carry up to 48 Normandy drop ships or Valkyrie combat shuttles and a squadron of fighters, plus 12 standard shuttles and two captain's yachts. During wartime the marines virtually live aboard these vessels, often sitting in deep space near conflict zones waiting for the order to jump in. But for almost all of the transit time they are kept in stasis to save on food, water and other consumables...their stasis tubes are programmed to slowly prepare their bodies for the environment on the planet where operations are to be conducted.
The Archangel is moderately armed, but not designed for ship-to-ship combat. It's massive missile and particle beam batteries are focused on planetary bombardment, meant to soften hardened stationary targets in preparation for landing. However, the ship also carries a number of heavy rail gun batteries designed to intercept missiles and enemy bombers that may get past the fleet's screening vessels.
I think the best analog for these ships would be the Rodger Young from Starship Troopers, or the planned America-Class amphibious assault vessels currently being designed by the U.S. Navy.