Use Tags and Smart Folders in Notes on your iPhone and iPad - Apple Support

Use tags to quickly categorize your notes so you can easily find them later. Just add one or more tags — like #work or #shopping — anywhere in any note. You can also use tags together with existing folders to search and filter your notes across multiple folders.

Organize your reminders with tags on iPhone - Apple Support (TM)

How To Quickly Organize iPhone Notes Using Tags & Smart Folders

Add and remove folders in Notes on Mac - Apple Support

7 Features Of Apple Notes That Would Never Let You Ditch It, by Nikhil Vemu, Mac O'Clock

Draw or write in Notes on iPad - Apple Support

How to use Smart Folders in Notes app on iPhone, iPad, Mac

Get started with Notes on iPad - Apple Support (TM)

Search and organize your notes in folders on iPod touch - Apple Support (SG)

View your notes on Mac - Apple Support

How to use Smart Folders in iOS 15 and iPadOS 15 – Apple World Today

Notes User Guide for Mac - Apple Support

Use and customize Control Center on iPad - Apple Support