Is Moonriver on Polkadot?

Excuse me, could you please clarify if Moonriver is indeed a part of the Polkadot ecosystem? I've been hearing a lot about this platform and its potential, but I'm still unsure about its exact position within the Polkadot network. Could you elaborate on whether Moonriver operates as a parachain or some other form of integration within Polkadot, and what benefits this relationship might bring to both projects and their respective communities? Thank you for your time and expertise in this matter.