Faster-Than-Light technology has advanced enough for you to travel your own galaxy with relative ease, allowing you to create a trade and political map, which constantly change as you gain more information.
Plan your travels and transport network through the stars. Let others worry about the smaller matters and travel your galaxy to manage your stellar empire. An empire you share with a few thousand other players. Coexisting with other empires in the vast galaxy. Peace, unrest, hostility or open war. You make the decisions together.
One single decision can steamroll a change of the power balance for an entire galaxy.