Ethereum rollups help scale the network by processing transactions off-chain.  
They bundle data and post proofs back to Ethereum.  
Optimistic rollups are cheaper but have long withdrawal delays.  
ZK rollups are faster but more complex to develop.  
Both reduce fees and congestion but rely on Ethereum for security.  
Choosing one depends on your needs—speed or cost.

Ethereum rollups are awesome because they make transactions faster and cheaper while keeping everything secure on the main chain