Polygon is a platform design to support infrastructure development and help Ethereum scale. Its core component is a modular, flexible framework (Polygon SDK) that allows developers to build and connect Layer-2 infrastructures like Plasma, Optimistic Rollups, zkRollups, and Validium and standalone sidechains like the project's flagship product, Matic POS (Proof-of-Stake). Polygon rebranded from Matic Network in February 2021 and pivoted towards supporting multiple Layer-2 infrastructure. It will continue to support the Matic POS sidechain and Plasma-based payment system, which currently hosts over 90 applications.