What chain is Aave on?

Could you please enlighten me on the blockchain platform where Aave resides? I've been hearing quite a buzz about it in the cryptocurrency circles, but I'm still a bit hazy on the specific chain it operates on. Could you break it down for me in a straightforward manner? I'm quite interested in understanding the technicalities behind its operation and how it fits into the broader crypto ecosystem. Your expert insight would be greatly appreciated.