One of the exciting features the recently finalized 3GPP Rel. 16 brings to 5G is the support for Integrated Access Backhaul (IAB). IABs have the potential to be a game-changer, especially for millimeter Wave (mmWave) deployments by solving the key challenge of backhaul. However, the traditional design of IABs offers low efficiency. In this article, I will take a deep dive into IABs, their deployment configurations, and most importantly, the techniques needed to improve their efficiency.