A swipe down from the top of the screen reveals your notifications, just as it has for some time now. However, a new Cover Sheet has replaced the Notification Center of old.
It's confusing, mainly because it looks just like your lock screen, but it's not the lock screen. And on top of that, only a couple of notifications are displayed unless you swipe up to view older alerts. It's weird and will take some getting used to.
There are times when the best way to explain something is to draw a picture. When composing an email, long-press and then select Insert Drawing from the pop-up. Draw, sketch or play tic-tac-toe and send it on its way.
With iOS 11, Apple is finally moving the volume control that used to take over the screen when you were watching a video. Instead of showing a giant, annoying volume graphic, Apple tucked the volume indicator into a corner of the screen. Woo!
Apple is once again trying its hand at a social-oriented service with Apple Music profiles. The first time you launch Apple Music after updating to iOS 11, the app walks you through setting up your profile and privacy settings. In the future, you can find your profile and the same settings in the For You tab with a tap on your profile icon.
If your power button breaks, you can still turn the phone off with a new Shut Down option in Settings > General. To turn your iPhone back on, you'll need to have a charging cable handy, as the iPhone will turn on the moment it's plugged in to charge.