Is Kusama on Ethereum?

Excuse me, could you clarify something for me? I've been doing some research on Kusama and I'm a bit confused about its relationship with Ethereum. I understand that both are blockchains and that they have their own unique features and purposes, but I'm wondering if Kusama is somehow built on top of Ethereum, or if they're completely separate entities? I'd appreciate any insight you could provide on this matter.