Is Avalanche part of Ethereum?

Excuse me, could you clarify something for me? I've been hearing a lot about Avalanche and Ethereum lately, and I'm trying to understand the relationship between them. Is Avalanche considered a part of the Ethereum ecosystem? Or are they two separate entities? I'm trying to wrap my head around this crypto world, and your insight would be greatly appreciated. Thank you for your time and assistance in clarifying this matter for me.