According to the Ethereum Foundation, the most notable change is EIP-4844 for proto-danksharding, which seeks to optimize gas fees for Layer 2 Network(L2) data and enhance the network's ability to handle greater transaction volumes via those secondary layers.

An Ethereum Layer-2 (L2) solution is a secondary framework or protocol built on top of the Ethereum blockchain. The main purpose of these solutions is to increase the network's capacity for transactions and improve scalability, without compromising on security.

That means L2 users get all the security benefits of Ethereum mainnet's decentralization without having to pay the often-high gas fees on Ethereum.

The Dencun upgrade, which occurred today will be enhancing the underlying architecture of Ethereum so that it can more efficiently process data. With it, developers have said that L2s will see their operation costs go down and that users will see transaction fees reduced by around 75%.