On iPad and iPhone, Focus Modes lets you stay in the moment when you need to concentrate, when you want to present, or when step away from your device.
When you set up a focus, you can customize settings on your device to automatically silence some notifications based on what you’re doing. You can also customize a home screen page that has only the apps related to your focus and make that page the only one accessible when you have the Focus turned on.
Learn all about Focus Modes at
Use Focus on your iPhone or iPad – Apple Support
You can also check out this quick YouTube video that will walk you through the feature.