What chain is Avalanche on Coinbase?

I'm curious to know, which blockchain network does the Avalanche cryptocurrency operate on when it's listed on Coinbase? I understand that Avalanche is a popular and innovative platform, but I'm not entirely sure which specific chain it utilizes. Could you clarify which blockchain network Avalanche is built upon when traded on Coinbase, and perhaps provide some additional context about the significance of this choice for users and investors?