Cardano Vasil Hard Fork Explained

“Plutus scripts don't get submitted on-chain until you're interacting with them, so ''every single time'' when you want to use a dApp you have to include the whole script as part of the transaction.

This makes the transactions bigger. Larger transactions result in higher fees and decreased throughput. CIP 33 (Cardano improvement proposal) changes this. It is one of the updates coming with the Vasil HFC event in June 2022

CIP 33 allows "reference scripts" to be attached to outputs, now you can push a script onto the chain and then you can interact with it via a reference; this is a very lightweight way to interact with a smart contract rather than having all of the app logic in your transaction.

So CIP 33 allows you now to just have a small address, like an email address that you include in the transaction and it points to the script that already exists on-chain. This makes transaction size smaller and increases the throughput.” -Sooraj

Full List of Proposals