Is BNB built on Ethereum?

I'm curious, could you clarify something for me? I've been hearing a lot about BNB recently, and I'm trying to get a better understanding of its technological foundation. Is BNB, in fact, built on the Ethereum blockchain? I've seen some comparisons and analogies made between the two, but I'm not entirely sure if they share the same technological backbone. Could you please elaborate on this point? It would greatly assist me in piecing together the larger puzzle of the cryptocurrency ecosystem. Thank you in advance for your clarification.