The subject OS upgrade for the iPhone and iPad has been released, and you've probably already installed it. If you'd like to learn more about the new features offered in this release, read the following two articles:
The second article above was written before iOS 11 was released, so it's possible some of the features mentioned didn't make it into the final release. Anyway, you may be overwhelmed by all the new features, and how to use them. I'm slowly working my way through them, and I'm overwhelmed.