Layer 1

A layer 1 blockchain is the foundational network. It has its own consensus mechanism, its own validators or miners, and its own native coin. It does not depend on any other chain for security. Bitcoin, Ethereum, Solana, Cardano, Avalanche, and many others are layer 1 chains, and they compete on speed, cost, security, and the size of their ecosystems.

Layer 1 chains face a well-known tension often called the blockchain trilemma: it is hard to be decentralized, secure, and highly scalable at the same time. Bitcoin and Ethereum prioritize decentralization and security, which keeps their base layer throughput low. Solana prioritizes throughput with higher hardware requirements for validators.

The two main strategies for scaling are to improve the layer 1 itself, through larger blocks or parallel execution, or to move activity to layer 2 networks that inherit the layer 1's security. Ethereum has chosen the second path, while Solana has chosen the first. Many users interact with several layer 1 chains, moving assets between them via bridges.