Firstly, Ethereum and Bitcoin have different purposes. Bitcoin was created as an alternative to fiat money and is intended to be a medium of exchange and store of value. However, Ethereum was created to facilitate smart contracts and dApps.
Secondly, the Ethereum and Bitcoin networks differ in many ways, such as their block times, consensus algorithms, and energy intensity. Ethereum uses a proof-of-stake consensus mechanism while Bitcoin uses proof-of-work, and Ethereum transactions may contain executable code while Bitcoin transactions are only used to record transaction information. Lastly, Bitcoin is limited to 21 million coins while ETH has no set limit.