Layer 1

A layer 1 is a base blockchain that processes and finalises transactions on its own network using its own consensus mechanism and native coin. Bitcoin, Ethereum, Solana, BNB Chain, Cardano and Avalanche are all layer 1s.

Layer 1s are responsible for security and final settlement. Making them faster usually involves trade-offs: larger blocks or quicker block times can raise the hardware needed to run a node, which may reduce decentralisation. This is often described as the blockchain trilemma.

There are two broad strategies for scaling. Some layer 1s, such as Solana, aim to handle high throughput directly on the base chain. Others, notably Bitcoin and Ethereum, keep the base layer conservative and push most activity to layer 2 networks, such as Lightning or rollups, that inherit some of the base layer's security. Competition between layer 1s is intense, and many "Ethereum killers" of past cycles have since faded.