To date, Bitcoin and Ethereum are two Digitalcurrencies that are well-known by all the active users within the ecosystem.
Yet, despite the known differences in terms of blockchain, structure and focus, the idea of being able to see them at the top of crypto ranking over time may suggest that btc can be compared to ether, perhaps in the context of connection, competition or even replaceability.

In general, unlike Sidechains that are born with the idea of improving the blockchain to which they refer without creating a new monetary effect, a new blockchain creates instead a real cryptocurrency that, once listed, enters the scenario of a financial or speculative competition with the first crypto par excellence, bitcoin.

The Ethereum blockchain, as well as all the others, are born with the aim of improving or differentiating from the peer-to-peer model designed by Satoshi Nakamoto. The first link between the two technologies could be the very fact that Vitalik Buterin,
the Russian programmer and founder of Ethereum, followed Bitcoin by writing articles for a blog before deciding to implement his ideas, which were initially designed to improve the bitcoin platform.

Are Ethereum and Bitcoin linked? And the difference
Find out the difference

https://www.techleague.net/2019/01/ethereum-and-bitcoin-difference.html