The current Ethereum Mainnet is scheduled to merge with the Beacon Chain, entirely switching to the Proof of Stake system in the first and second quarters of 2022. This merge means that the Ethereum blockchain will no longer run on a Proof of Work ecosystem. Once this step is implemented, all that will be left is the rollout of shards.
What are Mainnet and the Beacon Chain
Mainnet (short for “Main Network”) is the current main public blockchain used by Ethereum. It is secured by the Proof of Work system, which has high energy consumption and is considered harmful to the environment. To make its blockchain more eco-friendly, Ethereum has started its transition to a Proof of Stake system, with the first step being implemented in December 2020 with the introduction of the Beacon Chain (Phase 0).
The Beacon Chain is another blockchain used by Ethereum that operates parallel with Mainnet. You can think of it as the foundation for when Ethereum becomes Ethereum 2.0. The Chain uses a more sustainable Proof of Stake system, introducing “staking Ethereum” and developing a setting for “shard chains” (which will spread the network’s load over 64 new chains when implemented). However, unlike Mainnet, it does not handle smart contracts or accounts.
Next Step: The Merge
The Merge is the next step towards Ethereum’s goal of making its blockchain more secure, sustainable, and scalable. It will allow Ethereum’s two blockchains to finally become one. To ensure that all ETH holders and users transition smoothly, the final blockchain will include Mainnet’s ability to run smart contracts, as well as the current state and the complete history of Ethereum.
What Will Happen After The Merge?
Transitioning to the Beacon Chain’s Proof of Stake system will signal the beginning of a more eco-friendly and sustainable Ethereum. However, as simplicity is an integral part of this process, developers are concentrating their efforts on the merge of the systems and minimizing adding more features that could delay it.
Therefore, some of the features, including the ability to withdraw the staked Ethereum 2.0, will be implemented in a separate upgrade shortly after the completion of the Merge.
Last Step: The Shard Chains
In 2023, Ethereum plans to ship the last phase of its transition: the Shard Chains. By spreading the network’s load over 64 new chains, this phase will keep the hardware requirements low and make it easier to run a node. Also, Ethereum will acquire more capacity for storing and accessing data, though these chains won’t be executing codes. Details are still being considered, so nothing is set in stone.
To recap, Mainnet merging with the Beacon Chain will make Ethereum much more sustainable and eco-friendly. After introducing the Beacon Chain in December 2020, The Merge is the next step in Ethereum’s transition to Ethereum 2.0, leaving only Shard Chains to be added in the final phase (estimated to be in 2023). The unlocking of the Eth2 tokens will be done a little bit after the Merge is complete.