Having an iPhone with a nice camera and plenty of storage coupled with an album that lives in the cloud rather than on the device can lead to having an enormous amount of photos. This is especially true if you are the type that takes many shots of the same subject while planning on deleting all but the best one later, which invariably results in hundreds, if not thousands of duplicate photos taking up space on your camera roll.
If you are ever curious about what you were doing a year ago, the Photos app has a nifty shortcut to take you right to your pictures from that time. Just 3D press the Photos app icon to bring up the shortcuts. You can check out your recent photos, photos from a year ago and your favorites, as well as a few suggested albums with a simple tap.
If you owned an an early generation iPhone (or any camera phone or digital camera) before it was equipped with GPS, chances are you have photos in your camera roll that have no location information. iPhones now geotag your photos automatically (unless you have turned the feature off), which helps with categorizing them and allows them to import into your "Places" album. You can, however, add locations to your "dumb" photos using Apple's Photos app on a Mac. Here's how to do it:
The iCloud Photo Library was designed to let you easily sync your photos between all of your devices. If you have it enabled on your iPhone, then you can turn it on on your Mac or iPad and instantly access all the pictures you've taken with your iPhone. Additionally, any photo edits you perform on your Mac will immediately be reflected in those photos on your other devices.
The ability to take a screenshot has been around for a while and is useful for a variety of reasons, whether you are using them to write a tutorial about a game or just showing friends the contents of a message thread. Whatever your reason, annotating a screenshots can make them a lot more useful, and iOS 11 has overhauled the screenshot process to make it that much easier.