Is Avalanche a Layer 1 or 0?

I'm curious to know, is Avalanche considered a Layer 1 or Layer 0 blockchain? This question has been bugging me for a while as I delve deeper into the nuances of cryptocurrency technology. Layer 1 blockchains, as I understand, refer to the main blockchain protocols that support smart contracts and decentralized applications. On the other hand, Layer 0 is a newer concept, often associated with the foundational layer that enables the interoperability and scalability of various blockchains. Given Avalanche's reputation for its scalability and innovative architecture, I'm keen to hear your thoughts on whether it falls into the Layer 1 or Layer 0 category. Your insights would greatly assist me in my understanding of this evolving field.