Is AAVE on Ethereum or Polygon?

Could you please clarify for me, does the AAVE token reside on the Ethereum blockchain or is it instead situated on the Polygon network? I've heard conflicting information about this, and I'm trying to understand the specifics of its operational environment. If it's on Ethereum, does that mean it benefits from the security and decentralization that Ethereum is known for? And if it's on Polygon, how does that affect its scalability and transaction speed? I'm really curious to know more about this, as it could have significant implications for its use and functionality.