#Polygon styles itself as "Ethereum's internet of blockchains". In short, Polygon is a collection of tools and features which improve the scalability of Ethereum and connect EVM-compatible networks.
Recognizing that high demand for Ethereum mainnet has increased transaction fees and congestion, Polygon's solutions are intended to expand capacity and dramatically reduce transaction costs for users. Founded as Matic Network in 2017, the project has since rebranded and upgraded its token from #MATIC to POL.
From a user perspective, the main element of the Polygon project is likely to be the Polygon PoS (Proof of Stake) network and Polygon zkEVM network. Polygon PoS is an EVM-compatible, proof-of-stake sidechain for Ethereum; Polygon zkEVM is an EVM-equivalent, Layer 2 network for Ethereum.
Polygon has a highly active ecosystem of dapps, including DeFi, gaming, and NFTs — all recorded here.