And you can store full-resolution photos in iCloud and keep what Apple calls 'optimized' versions on your Mac that take up much less space. You can move all the files stored on your desktop and Documents folder from your Mac's drive to iCloud.

The first lets you use iCloud to offload files, photos and text messages. Here, you'll see four recommendations for reclaiming free drive space. If you are approaching maximum capacity, click the Manage button to free up some space. You can check out how much free space remains on your MacBook's drive by clicking the Apple logo in the top left, select About This Mac and then click the Storage tab. The more crowded its SSD becomes, the slower it will run. Sometimes, all your MacBook needs is a data cleanup. With your Mac's drive freshly backed up, you may proceed. Grab an external drive and run Time Machine.