Fleets are compiliations of ships. The fleet size is simply the total number of credits used for the production of the ships. Players are able to name each fleet with a unique name, which makes it simple to find a specific fleet.
"Mobile fleet" is a term used to describe a fleet that a player frequently moves from planet to planet. Players can only have a certain amount of mobile fleets, equal to the number of command centers. Fleets takes time to move from one spot to another, but can be expedited by using jumpgates. Fleets may be recalled to the original position by selecting the fleet and choosing recall.Edit