Definition ∞ Network Layer One refers to the foundational blockchain protocol itself, such as Bitcoin or Ethereum. This base layer processes and validates transactions directly on its main chain without relying on other networks for security. It establishes the core rules and consensus mechanisms that govern the entire system. All subsequent layers and applications build upon this fundamental infrastructure.
Context ∞ Discussions about Network Layer One often center on its security, decentralization, and scalability limitations. Major upgrades or changes to a Layer One protocol, like Ethereum’s transition to Proof of Stake, are significant news events. The performance and capabilities of this layer directly impact the functionality and adoption of the entire ecosystem built upon it.