According to Apple, Notes is one of the most popular and most-frequently used stock applications on the iPhone, iPod touch and iPad.
People use Notes for everything from memorizing recipes to keeping track of errands, creating shopping lists, storing inspirational quotes and even passwords, codes and medical data.
Not all notes contain sensitive information, but many do. Beginning with iOS 9.3 and OS X El Capitan 10.11.4, you can protect your notes with a password or Touch ID.
In this tutorial, you'll learn how to set up Notes protection, secure items on a note-by-note basis so no one can view their contents and more.