Layer-2 refers to a secondary framework or protocol built on top of an existing #blockchain (Layer-1). Think of [[Layer-1]] as the foundation of a house, and Layer-2 as the added rooms and floors built on top. Layer-2 solutions are designed to improve the scalability and efficiency of the underlying blockchain by handling transactions off-chain, then settling them on the main blockchain periodically. This helps reduce congestion and transaction fees on the main chain, allowing for faster and cheaper transactions. Popular examples include Polygon, Arbitrum, and Optimism. See also [[Ethereum]]