Did you know Apple has what amounts to an online manual for iOS 26 and the iPhone? Once you get into a specific topic from the table of contents, you can select older versions of iOS, too. Or, just change the version number in the URL.

https://support.apple.com/guide/iphone/welcome/26/ios

iPhone User Guide

Here’s everything you need to know about iPhone, straight from Apple. This definitive guide helps you get started using iPhone and discover all the amazing things it can do.

Apple Support
@dsilverman It's also available on the phone itself. You can get to it from the tips app and in settings.
@KaraLG84 Thank you! Where exactly in Settings?
@dsilverman @KaraLG84 I think she is referring to the App, Tips. I don’t recall getting it from App store, it just showed up on day several years ago. I probably forgot I downloaded it. Anyway, in my settings it is in the apps section.
@jfharrison @dsilverman Yes but you can also get to it via settings.
@dsilverman Press any of the help text it shows at the top of a screen.
@KaraLG84 Oh, that's very interesting. Works on the Mac, too, with the macOS guide.