Why the Ethereum Update is Delayed (Yet Again)
Now known as "The Merge", the Ethereum (CRYPTO: ETH) upgrade will transition the blockchain from a Proof of Work consensus mechanism to the more efficient and less energy intensive Proof of Stake method.
In addition, there will be a handful of other upgrades that will help Ethereum tackle the slower speeds and high fees that have plagued the blockchain when traffic is high. But in order for this merge to take place, developers must implement smaller steps before completely migrating to Proof of Stake. One of those steps is known as the difficulty bomb.
The difficulty bomb is a piece of code added into Ethereum's code back in 2015 to help this transition. One of the worries from the Ethereum community is that miners will not be incentivized to move to Proof of Stake. To combat this, developers created the difficulty bomb.
Source Fool.com