Set up iCloud Photo Library >
1 Use the correct library
If you already use multiple libraries with Photos and the most recent one opened isn’t your System Photo Library, hold å and open Photos, then choose the System Photo Library from the list.
2 Enable it on a Mac
In Photos’ iCloud preferences, turn on iCloud Photo Library. You can check on upload progress here, and pause it for a day if, say, you need to switch from broadband to a mobile data connection.
3 Enable it on iOS devices
Go to Settings > iCloud > Photos and switch on iCloud Photo Library. If your device has little free space, switch the setting below so that the device receives photos at a quality that’s optimised for it.