According to binance academy:
The Ethereum Arrow Glacier Upgrade is a fairly simple update implemented in block number 13,773,000, Dec 9, 2021.
This will then delay the network's difficulty bomb, allowing developers more time to prepare Ethereum 2.0. Extending the said difficulty bomb is a regular part of Ethereum's upgrades.
Another thing, you might be wondering about what difficulty bomb is.
The difficulty bomb was made to gradually increases the difficulty of the mathematical puzzles needed to be solved in order to mine, making it more costly to mine a block successfully. At some point in the future, the difficulty bomb will "explode" and make it almost impossible to validate transactions and add new blocks and it is also said that this will cut energy consumption by more than 99%.
There are two main reasons as to why the Ethereum network added the difficulty bomb:
1. To help motivate the development of Ethereum 2.0 and the move to a Proof of Stake model (PoS).
2. To force miners to upgrade to the new PoS blockchain, as they will not be able to keep mining Ether (ETH) on the old PoW version of Ethereum. This will prevent the creation of two conflicting Ethereum networks through a hard fork.
