Is AVAX the same as Ethereum?

Excuse me, I have a question about cryptocurrencies. Could you please clarify for me whether AVAX is essentially the same as Ethereum? I've heard that both are smart contract platforms, but I'm not entirely sure about the nuances between them. Could you elaborate on the similarities and differences between these two cryptocurrencies? I'm particularly interested in understanding their functionalities, use cases, and any potential advantages or disadvantages they might have. Your insights would be greatly appreciated. Thank you in advance for your help!