Layer 0
In short: Layer 0 is the network structure that runs underneath a blockchain system. It includes elements such as the protocol, connectivity, hardware and miners…
Layer 0 is the network structure that runs underneath a blockchain system. It includes elements such as the protocol, connectivity, hardware and miners that together form the foundation of the blockchain ecosystem.
Why it matters
Every blockchain depends on this base: nodes need hardware to run on, internet connections to reach one another, and shared rules for passing data. The term is also used for frameworks that let developers launch several Layer 1 chains that share infrastructure and can exchange messages with each other. Such frameworks aim to make new chains easier to build and to improve interoperability, so tokens and data can move between chains instead of staying locked in one.
Example
Picture a framework that provides shared networking, security and messaging standards. A team building a blockchain for games plugs into it instead of designing everything from scratch, and its chain can then swap tokens and data with other chains on the same framework. In this picture, the framework plays the Layer 0 role, the game chain is a Layer 1, and scaling solutions built on top of that chain would be Layer 2.