This is the USS Ticonderoga, the first in her class. It is a ship in a Star Trek universe where, due to a much more war-weary foundation of the Federation, Starfleet is much more militarized. Not that they're aggressive, but they certainly don't send ships out that are unable to defend themselves. As one can tell, the Ticonderoga was very much meant to be a combat ship. The deflector dish and warp nacelles are as tucked away under the saucer as they can be, in order to keep them out of harm's way as much as possible (seriously, the Enterprise-D had her nacelles shot up so much it's not even funny). The saucer contains in its entirety the engineering section of the ship, and as such the lower section of the ship is freed up for other purposes. Namely, to serve as a flight deck (which you can see protruding out) and hangar bay for fighters, bombers, and diplomatic shuttles.
During normal operations, there is a "fighter bridge" active just above the flight deck while the main bridge handles things for the rest of the ship. In combat, however, both bridges are closed as the command crew meet in a bridge in the middle of the ship, referred to in Trek terms as the "battle bridge" but really a CIC. There, ship-to-ship combat as well as direction of the fighter and bomber crews can be done, complete with a table that can function as a manual tracking of battle or project a 3D holographic spherical display to track the battle in real time on a 3D plane rather than a flat surface. Armaments of the ship include both top and bottom phaser banks, proton torpedo tubes, and burst-fire phaser cannons that can be retracted into the ship to keep them from being hit.