What chain is Moonbeam on?

I'm curious, could you please clarify which blockchain network Moonbeam is built upon? As a seasoned professional in the field of cryptocurrency and finance, I understand the importance of understanding the underlying infrastructure of various projects. Moonbeam has been making waves lately, and I'm eager to learn more about its technical foundations. Is it an Ethereum-based solution, perhaps leveraging the ERC-20 standard or Polkadot's interoperability? Or does it operate on a completely different blockchain altogether? Your insights would be greatly appreciated.