Is Zilliqa layer 1 or 2?

Could you please clarify for me if Zilliqa is classified as a layer 1 or layer 2 blockchain platform? I've heard differing opinions on this matter and I'm interested in understanding the specifics behind its categorization. I'm particularly curious about how its sharding technology and scalability features factor into this determination. Additionally, I'd appreciate any insights you might have on how this classification impacts the platform's potential use cases and adoption within the blockchain and cryptocurrency ecosystem.