Polygon can be defined as a four-layer system composed of the Ethereum layer, security layer, Polygon networks layer, and execution layer.
- The Ethereum network is implemented through smart contracts that handle transaction finality, staking, and communication between Ethereum and the various Polygon chains.
- The security layer runs in parallel with Ethereum and provides a "validators as a service" role which allows chains to benefit from an additional layer of security.
- The Polygon network layer, or the ecosystem of the blockchain networks built on Polygon. Each has its own community and is responsible for handling local consensus and producing blocks.
- The execution layer which is Polygon's Ethereum Virtual Machine (EVM) implementation used for executing smart contracts.
Chains that run on the Polygon network are able to communicate both with one another and with the Ethereum main chain thanks to Polygon's arbitrary message passing capabilities. This allows for a variety of additional use-cases, such as interoperable decentralized applications (dApps) and the exchange of crypto between diverse platforms.