The term battlecruiser designates large warships such as the Farragut Battle Cruiser and Majestic Class Interdictor.
These are a type of Capital Ship designed to partake in space warfare. They carry less armour than battleships in order to gain faster speeds. They occupy a position between cruisers and battleships. They're typically the largest and strongest warships that aren't battleships.
Battlecruisers can also carry out ambassadorial missions with ‘soft’ power projection, as well as hard.[1]