Apple has debuted a new gift card that can be used with products, accessories, apps, games, music, movies, TV shows, iCloud, and more. Previously, there were several cards for Apple Store hardware, the App Store, and iTunes (naturally, you can still use any such cards).
You can redeem Apple Gift Cards or add money directly into your Apple Account Balance anytime. Note that these gift cards are solely for the purchase of goods and services from the Apple Store, the Apple Store app, apple.com, the App Store, iTunes, Apple Music, Apple TV, Apple Books, and other Apple properties. Should you receive a request for payment using Apple Gift Cards outside of the former, you should report it at FTC Complaint Assistant.