The Ethereum Merge has brought about numerous debates in the cryptocurrency community, largely due to curiosity about the operation mode of the new version of the most used blockchain network - Ethereum. Hence, there have been several myths amid very few facts, one of which is whether the Merge will result in a hard fork. First, let us understand the concept of a hard fork.
What is A Hard Fork?
The blockchain is a public ledger made up of several interconnected blocks; each block contains several transactions. For example, over 750,000 Bitcoin blocks have been mined; nevertheless, if we trace the blockchain back to the first block, we will see details of all the first set of transactions made on the Bitcoin network. However, this is only possible because the search is done on the “straight” Bitcoin blockchain and not hard-forked versions like Bitcoin Cash and Bitcoin Gold.
A hard fork is a permanent change to the source code of a network such that it is no longer backward-compatible with older blocks. Hence, the first transaction after a hard fork becomes a new “genesis block.” On the other hand, Bitcoin soft forks like the SEGWIT are backward-compatible; hence, SEGWIT Bitcoin shares the same genesis block as the “straight” Bitcoin blockchain.
If you are confused, consider the illustration below.
The initial (unforked) blockchain is in blue with some set of rules; however, due to some disagreements between network participants, a new set of rules (marked in red) are created, which is branched out from the straight blue blocks. If the new set of rules is incompatible with the old ones, it is considered a hard fork; however, if they are compatible, it is a soft fork.
Will ETH 2.0 Result In a Hard Fork?
Similar to Bitcoin, Ethereum has experienced hard forks in the past, which led to the emergence of Ethereum Classic, EtherZero, and Metropolis. However, ETH 2.0 will not result in a hard fork. Why?
Indeed, the network upgrade is being implemented as a separate chain (the Beacon chain). However, rather than forking the blockchain, the protocol will migrate ETH 1.0 contracts and accounts to one of the 64 shard chains on ETH 2.0. Similarly, ETH will remain the native token of the blockchain as it is on ETH 1.0.
In fact, given that the upgrade will involve a migration and not a “branch” or “split,” there is neither a hard fork nor a soft fork. Since all parties mutually agree, here are the changes to expect from the network upgrade.