The labels
HD is 720p, Full HD is 1080p and 4K is Ultra HD. The HD badge on every title page means the title had a proper high-definition release.
How the apps choose
Streaming apps adjust the picture to your connection automatically, and let you choose it yourself in their settings: Data Saver on a phone plan, High or Best on home Wi-Fi.
Where 4K shines
House of the Dragon, The Last of Us, Shōgun and Fallout look spectacular in 4K on the premium plans of their services.
Sound
Premium plans often add Dolby Atmos sound, which makes the battles of Game of Thrones feel huge on a good speaker.
