'Outer' in the Bible

Meanwhile, David was sitting between the inner and outer gates of the city. The watchman was up on the roof of the gateway near the walls, looking around, and there was a man running by himself!

Joab’s troops came and besieged Sheba in Abel of Beth-maacah. They built an assault ramp against the outer wall of the city. While all the troops with Joab were battering the wall to make it collapse,