Tim Hardwick, MacRumors:
In iOS 15, Apple introduced a new Focus feature that aims to help reduce distractions and let you zone in on a single thing. Focus does this by filtering notifications based on what you’re doing.
If you don’t have access to the iOS or iPadOS 15 beta, this is worth a look. Tim Hardwick does a nice job walking through the new Focus interface, exploring the full tree of options.
A short read, but it’ll give you a sense of how to set up and enable a Focus once you do have access.