iCloud Family Sharing is a great way to share content from iTunes and the App Store with your family members. If you have two children with similar taste in music, you can avoid buying the same song from iTunes twice by adding it to the shared family library. It also helps parents monitor what their kids are spending money on, as all purchases must go through an adult “Family Organizer”. Setting up Family Sharing is easy, and you can have up to 6 members in a family. As the Family Organizer, once everything is set up, you will send invitations to 5 other people to be part of your Family Sharing plan, and when they accept the invitation, their devices will make any necessary changes automatically.
On an iOS device running iOS 8 or newer, go to “Settings”, select “iCloud” and go to “Set Up Family Sharing”.
On your Mac computer, go to “System Preferences”, select “iCloud” and then click on “Set Up Family Sharing”.