A layer-1 network (L1) is another name for a base blockchain. Bitcoin, Ethereum, Solana and BNB Smart Chain are all layer-1 networks. We refer to them as layer-1 because these are the main networks within their ecosystem. Layer-2 blockchains might be built on top of these L1s in order to scale the base layer and improve on some of its functionalities. Ethereum for instance suffers from high transaction fees especially when the network is busy, that’s why L2 solutions like Immutable X and Arbitrum were created. Solana, despite its fast transactions, has been suffering from persistent congestion issues but no L2 solutions have been implemented yet. Anyways, in both cases, we colloquially refer to these base blockchains as “L1s”. Most of them support smart contracts, and encompass a plethora of projects (ecosystem coins) but I would avoid those in such bearish times!