What is Layer-1 Blockchain?

A Layer-1 blockchain is typically a name used to describe a main blockchain network protocol such as Ethereum or Bitcoin. The name Layer 1 comes from its relationship with Layer-2 scaling solutions such as state channels, rollups, nested blockchains, and plasma sidechains. Layer-1 blockchains are simply the main network that a Layer-2 scaling solution attaches to in order to improve the scalability and transaction throughput of the mainchain, or Layer 1. Layer-1 blockchains can also be known as the parent chain or root chain, among other classifications.