Change preferences in Photos on Mac
To change preferences in the Photos app on your Mac, choose Photos > Preferences, then click the General or iCloud button at the top of the preferences window.
In the General pane, you can change basic Photos preferences. For example, you can set whether photos are shown in a “summarized” view, select whether imported items are copied into your library, select whether GPS information is included with photos, and more.
To view the location of your Photos library in the Finder, click Show in Finder. 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. For information about how to switch libraries, see System Photo Library overview and Create additional photo libraries.
To display your photos in a summarized view that shows only a selection of thumbnails for each year or collection, select the “Summarize photos” checkbox. To show thumbnails of all photos in a collection or year, deselect this checkbox.
To include groups of holiday photos as memories, select the Show Holiday Events checkbox. To exclude holiday photos from your memories, deselect this checkbox. To see a notification when a new memory is available, select the Show Memories Notification checkbox. If you have blocked certain types of memories but want to create these types of memories again, click Reset Blocked Memories.
By default, Photos stores all imported photo and video files in the Photos library. To leave imported items in their current location outside of the library, deselect the “Copy items to the Photos library” checkbox. If photos are stored outside the library, they will not be automatically uploaded to iCloud Photos and available on all your devices. You must manually back them up to safe storage locations.
To have Photos use location information embedded in photos taken by a GPS-enabled camera (including iPhone), select the “Include location information for published items” checkbox.
Select the checkbox to turn on iCloud Photos.
Note: If Optimize Mac Storage is selected and you’re running low on storage space, Live Photos are stored on your computer as still images. However, when you open a Live Photo, the entire photo plays as usual.
For more information about iCloud Photos, see Use iCloud Photos to store photos.
My Photo Stream
Select this checkbox to turn on My Photo Stream. My Photo Stream automatically transfers new photos to all your other iOS devices and computers that have My Photo Stream turned on. My Photo Stream only stores photos taken in the last 30 days (up to 1000 photos); it doesn’t permanently store your photos. See Use My Photo Stream to share recent photos.
Select this checkbox to share albums with others and subscribe to albums that others share with you. You can select photos and share them with friends and family; people you share with can view the photos, make comments, and even add photos of their own. See What are Shared Albums in Photos on Mac?