Is Ethereum related to Bitcoin? Does any one know whether they are related or not?
Hardly related at all actually.
Bitcoin generally has a community which cares about decentralization in the form of the following: lots of full node runners, acceptable mean fee rates, upgrades through softforks and user facing consensus, slow and secure approach to what goes into the software.
Ethereum community generally is willing to sacrifice decentralization for what I would refer to as "shiny objects" like artificially fast block times (with really slow finality), fee bidding wars that increase profit for the large organizations responsible for approving blocks, censorship capabilities: https://www.mevwatch.info/ , "turing completeness" which basically just means you can use it for things you should not be able to and practically would not if you were sane, and creating tokens out of thin air with 0 effort involved. Not sure why they like these things but that is basically what Ethereum is. Source: Mined Ethereum since 2020 was not informed about "the merge" until halfway through, sold all my Ethereum promptly upon learning the truth about how centralized their operation is.
Note: During the entire ~2 years that I mined ETH I was forced to use a centralized rollup called polygon to even have a hope of avoiding fees, this means I was paid in an IOU version of ETH called wETH. Technically I did save fees but only because I trusted a random organization with all my profits in the form of daily IOUs, on a fundamental level that is incredibly insecure and a shame that they tell people it is. But the point is as a miner for 2 years I was not even able or willing to use the base layer as sending 1$ cost 4$ even today. Selling wETH daily to USDC and offloading to a CEX every week is the only reason I profited and I have 0 regret there.