In simple terms, "The Merge" is a change to the Ethereum network infrastructure that initially they used PoW (Proof-of-Work) consensus and then changed to PoS (Proof-of-Stake). Ethereum did this "The Merge" on the basis of scalability, as we know that in recent years the Ethereum network has experienced bottlenecks in its network, this has caused an increase in fees for transactions and it has become a problem for people in crypto. After "The Merge", that problem no longer exists, you can see it on this page.

Due to the change in consensus from PoW to PoS, currently we don't know the name Miner for the Ethereum network anymore, we only know Staker, LOL.