Bitcoin and Ethereum are the two popular cryptocurrencies, these coins have some correlations, even though they have some distinctions.

Ethereum was created and founded by blockchain developers; it was a world-programmable blockchain. Bitcoin Blockchain only supports BTC as a payment method.

The entire supply circulation of bitcoin is 21 million but coming to Ethereum the supply is unlimited. Till now 120 million Ethereum is supplied to the whole world.

Another key difference between Ethereum and Bitcoin is their handling of transaction processing fees. 

On the Ethereum network, these fees are known as gas, which participants in Ethereum transactions pay and the network subsequently burns. 

In contrast, Bitcoin transaction fees are paid to Bitcoin miners.

Ethereum uses a proof of stack consensus mechanism, and Bitcoin uses a proof of work consensus mechanism. 

The difference between each mechanism is that proof of work consumes more computational power and involves solving complex mathematical problems but proof of stack doesn't need much like the bitcoin mechanism.