The term "mothership" is used to describe a large spaceship or spacecraft that serves as a central command and control center for other smaller ships, vehicles, or crafts in its fleet. The name comes from the idea that the mothership acts like a mother bird watching over her chicks - all the smaller vessels are under its protection and guidance. In popular culture, the term is often used to describe a UFO or alien spacecraft that is much larger than any other vehicles seen near it, suggesting that these smaller crafts may be part of the same group or civilization as the mothership.