Is Moonriver proof of stake?

I'm curious, could you please clarify if Moonriver utilizes a proof-of-stake consensus mechanism? As an individual invested in the world of cryptocurrency and finance, understanding the underlying technology behind various blockchain projects is crucial for making informed decisions. If Moonriver does indeed employ proof-of-stake, how does this factor into its overall security, scalability, and environmental impact compared to other consensus mechanisms? I'd appreciate any insights you can provide on this matter.