Exploration stations are stations that are designed to travel to other planets and stay in orbit of it for a period of time. They have no military capabilities and have enough resources to last on its own without being resupplied for a long period of time. Some exploration station designs incorporate artificial gravity modules to keep the crew onboard healthy so they can stay on the station for longer. New stations can also have air locks, as the crew would likely have to perform spacewalks to repair the ship from time to time.
With the new space station engine parts exploration station can now be much more compact as they do not need room for large solar panels.