A consensus mechanism is the core component of a blockchain network, which ensures that every participant agrees on the state of the network in trustless environments. Until now, current blockchain networks have been using the proof-of-work (PoW) consensus mechanism, which has serious limitations such as huge energy consumption, low transaction processing capabilities, and centralization and scalability issues. To overcome these problems, a new consensus mechanism entitled proof-of-stake (PoS) has been developed. PoS has many advantages, including negligible energy consumption and very low consensus delay. Ethereum (the largest decentralized global software platform to create secured digital technology powered by blockchain technology and the blockchain of choice globally for all developers and enterprises) has just switched from PoW to PoS. As a result, this mechanism is expected to become a cutting-edge technology for future blockchain networks.