Ethereum (ETH)
Ethereum (ETH) is the second most popular cryptocurrency launched in 2015 by Vitalik Buterin and his team. In addition to a huge number of transfers and transactions, it allows programming by using smart contracts.
Like in the case of BTC, ETH initially used the PoW consensus mechanism but switched to a more environmentally friendly and energy-efficient proof-of-stake (PoS) model. Such a transition allowed users to confirm transactions and ensure network security by using their ETH, rather than using nodes and computing power.