Large fictional capital military spacecraft (frequently called space battleships, space cruisers) are spacefaring warships most often found in science fiction, which play similar roles to contemporary warships, though real spacecraft are used for military purposes. They may fight slow-paced battles across vast distances with long range guided weapons, never attaining visual contact, or fast-paced, relatively close range combat with unguided weapons and combat maneuvering.
Smaller "space fighters" are fictional spacecraft analogous to fighter aircraft. Space fighters are popular as the subjects of flight simulator-like space combat video games, such as the Wing Commander, Freespace and X-Wing series. For examples, see this list of space fighters.
In addition to various military science fiction-typical parallels derived from historic and existing naval customs and technologies (see Space navy), fictional space battleships also often have some specific sea warfare battleship parallels, especially to those used in World War I and World War II:
In science fiction, the meaning of the word "battlecruiser" is generally different from the historical warship of the same name. Usually it denotes a spaceship midway between a cruiser and a battleship in size and firepower. An example are the battlecruisers from the Honorverse fiction. The closest historical version would be the Alaska-class cruisers which the United States deployed during World War II. The Alaska class carried 12" guns while cruisers of the time carried 8" and battleships carried 16". But historical battlecruisers were an attempt to create a faster battleship by reducing armour. While having the same dimensions and gun calibers, a battlecruiser would carry only a 6" armour belt while a battleship would have 12".