A hive-mind of assimilated species that pursues perfection by absorbing the technology and bodies of others. Resistance, they say, is futile.
The Borg are a cybernetic collective who travel through space in cube-shaped ships and assimilate other species into their ranks. Individual drones have mechanical implants and share a single hive mind, and their voices speak as one. They do not negotiate, and they adapt very quickly to any weapons used against them.
Their goal is perfection through the absorption of technology and biological traits from every species they meet. The collective is guided by a Borg Queen, who gives the hive a voice and a will, and the drones themselves have little personal identity. The Borg are thought to have originated in the Delta Quadrant.
Q introduces them to the Federation in the Next Generation episode Q Who. In The Best of Both Worlds, they capture Captain Picard and make him Locutus, a spokesman for the collective, and the battle at Wolf 359 destroys much of Starfleet's fleet. Later, Hugh, Seven of Nine and the Borg Queen become prominent, and the film First Contact takes the crew back in time to stop the Borg from altering Earth's history.