iCloud Links
When you turn on the iCloud Photos feature on your device, you can share photos and videos with an iCloud Link using your iPhone, iPad or iPod touch, or on iCloud.com (not available in all countries or regions). Anyone with the link can open the photos. iCloud Links expire after 30 days.
When you share an iCloud Link, people you share with may be invited to add photos and videos that were taken around the same time and place. See Share photos and videos in the iPhone User Guide.
iCloud Links are different from Shared Albums. To learn more about Shared Albums, see the Apple Support article How to use Shared Albums in Photos on your iPhone, iPad and Mac.