Polygon PoS is a sidechain. Polygon has a lot of other L2 solutions including zk rollups in the works that are true L2 solutions. But the original is a sidechain, which some people consider L2 if you broaden the definition to include sidechains as well.
Polygon PoS is a sidechain. Polygon has a lot of other L2 solutions including zk rollups in the works that are true L2 solutions. But the original is a sidechain, which some people consider L2 if you broaden the definition to include sidechains as well.