The Borg cube was the primary starship class of the Borg Collective's fleet. Borg cubes are designed as a combined weapons platform and factory. Their main purpose was for destroying the military capacity of a species and assimilate the survivors into the Collective. Starfleet designated these ships as dreadnoughts. In the first few years after the first were encountered by the Federation, they were also known simply as a "Borg vessel." (ST reference: Star Trek Encyclopedia, CCG set: First Contact, Decipher RPG module: Starships, TNG video game: Echoes From the Past) Among other starship classes of the Borg fleet, the Borg cube went through three different versions in the 22nd, 23rd and 24th century respectively. (ST video game: Legacy)