Question: What are the Barracks?
The term "Barracks" was first introduced in Episode 3x11, Enter 77.
Answer: Sayid finds a map in the Flame Station that showed electrical and data cabling, running from The Flame, to a place called the Barracks. It's comprised of buildings and dormitories and water and power, large enough to accommodate an entire community.
Sayid leads Mikhail, Rousseau, Locke, and Kate to the Barracks where they find Jack playing football with Tom.
The Barracks are where the Others lived until they were discovered by the survivors of Flight 815. The Barracks had been built by the Dharma Initiative.
After going back in time, Sawyer, Juliet, Jin, Miles and then later Jack, Kate, Hurley, and Sayid live at the Barracks (Ep: 5x8, LaFleur and Ep: 5x9, Namaste).
