The singleplayer mode is basically the same as the cooperative mode. A great difference between these modes and the multiplayer team bases game mode are the given objectives. In the upper right corner the actual tasks are shown. The better you perform in fulfilling the objectives the better your ground forces keep pushing forward.
There are two basic game modes. The one is Domination, the other Frontline.
They differ by the way victory can be reached and by the abilities ground units have.
It’s about capturing and holding bases. Each owned base gives a specific amount of points. When one team reaches the limit, this side wins the game. But that’s what the ground forces care for. Your job: fulfill the objectives!
In this game mode, convoys made of armored vehicles are much more important. It’s about leading a convoy to the stronghold of the other side.
So, basically, if you play the domination mode it doesn’t matter which bases you own as long as you own the majority. But if you play the frontline mode it’s important to move forward. Keep this in mind if the objectives leave you some time to decide something on your own. But again: That’s what the ground forces care for. Your job: fulfill the objectives!