They used hovercraft technology to achieve flight and were generally not equipped with warp cores due to the danger of a warp core breach in the atmosphere. They were commonly armed with phasers or disruptors and missile launchers. They commonly had a crew of four and the ability to carry several passengers. Some were outfitted as troop carriers or couriers.
The Starfleet Ground Forces had air units equipped with armored assault craft. (The Dominion War Sourcebook: The Fires of Armageddon)