The best part, in my opinion, of Star Trek Online are the starship battles, but the ground missions are fairly good, as well. In most of them, you and your faithful Bridge Officers (BOFFs) fight enemies and scan things and fix broken things and generally save the planet. It is important to choose your BOFFs to have a wide range of skills available. Science officers can heal you and disable or slow enemies, while engineering officers refill your shields and summon turrets and generators to help with health and shields, and tactical officers throw grenades and can buff the team. All these are in addition to your skills.
If you are playing as part of a team, then you and your teammates may end up with fewer BOFFs each on a particular mission, but not always. There are a few large ground battles where it is just you and other players against lots of enemies, but you don’t get the BOFFs to help you. Overall, it’s a pretty nice system and you’re never lonely when you have your BOFFs to talk to…