iTunes gift cards, you can get music, movies, series, apps, e-books, audio subscriptions
With iTunes gift cards, you can get music, movies, series, apps, e-books, audio subscriptions, Apple Music subscriptions, and more on Apple devices running your iOS operating system.
When you use an iTunes gift card, the credit will be added to your Apple account, then used in the iTunes Store, the App Store or the iBooks Store as long as you have signed in to each Of those stores with the same name as your user on Apple, and you can use the added balance for each purchase you make on the store until the balance ends.