Is Ethereum 1 the same as Ethereum 2?

Could you please clarify for me the difference between Ethereum 1 and Ethereum 2? Are they essentially the same thing, or are there distinct differences that separate the two? If they are not identical, could you highlight the key differences between them? I'm trying to understand the evolution of Ethereum and how these versions fit into the larger picture of blockchain technology. Thank you for your assistance in clarifying this matter.