If you don’t want videos and Live Photos to play automatically, deselect this checkbox. To have videos and Live Photos play automatically, select the Autoplay Videos and Live Photos checkbox. For information about how to switch libraries, see System Photo Library overview and Create additional photo libraries. To use the currently open library as your System Photo Library (which allows you to use it with iCloud Photos), click Use as System Photo Library. To view the location of your Photos library in the Finder, click Show in Finder.
