What is a Layer-1?

Layer-1 blockchains are the foundational protocols that handle transaction processing, consensus mechanisms, and security directly on their main blockchain, serving as the primary infrastructure layer upon which the entire ecosystem of applications and services is built.

These networks maintain their own independent validators or miners, consensus rules, and native cryptocurrencies, establishing the core security guarantees and trust assumptions that all applications built on top of them inherit and depend upon for their operation.

Major Layer-1 blockchains like Bitcoin, Ethereum, Solana, and Cardano each make different design choices regarding their consensus mechanisms, programming capabilities, transaction throughput, and decentralization, creating distinct ecosystems with unique strengths and limitations.

As blockchain adoption grows, Layer-1 networks face the inherent challenge of balancing the three critical properties of security, decentralization, and scalability (the 'blockchain trilemma'), with most optimizing for two of these properties at the expense of the third.

The evolution of Layer-1 technology continues through protocol upgrades, hard forks, and architectural innovations, with networks competing to provide the optimal foundation for the growing decentralized economy while maintaining the essential properties that make blockchain technology valuable.