Computer Games - Empire at War also allows players to actually move and conquer whole star systems. How does this aspect of the game fit in?

Joe Bostic - The player constructs ships and armies, marshals them into fleets, and sends the fleets to enemy controlled systems. Securing control of space by way of space combat is the first order of business. Space combat is dangerous since the invasion transports are vulnerable and there may be weapons on the planet’s surface that can fire upon the fleet, such as an Ion Cannon. If the space battle is successful, a land invasion is next. The player sends initial scouting forces (pathfinders) to the surface and then calls in any supporting reinforcements from available troops in orbital transports. Battle is engaged on the surface until one side or the other is defeated or retreats.