Proposer Build Is Separation Is a Form of MEV Boost

Proposer Build is Separation will be enshrined into the Ethereum protocol itself at some point. Eventually there will be an actual auction where builders are going to submit their bids and Proposers just pick among them. The way that it works today is what's called MEV Boost which is a form of Proposer Build was Separation. It's basically just an earlier version of what ETH will eventually implement with Proposer builder separation.