iCloud
How do I upload the photos from my MacBook Air to icloud
MacBook Air 11", OS X 10.11
See the following: Set up and use iCloud Photos - Apple Support
Note that iCloud Photos is a syncing service and the photos will also remain on your MacBook Air and on any other devices where you have iCloud Photos turned on. You can potentially reduce the space required on a device by turning on the Optimize Storage option. That is discussed in the article linked above.