At the base of Fluid lies the Liquidity Layer, which serves as the foundation upon which other protocols can be built. This layer serves as a central hub where liquidity from all protocols is consolidated. It facilitates automated limits for protocols, manages utilization rates, and can deploy various rate models. The Liquidity Layer allows protocols to deposit, withdraw, borrow, and payback. End-users interact with the protocols, which in turn interact with the Liquidity layer.