If you want to cast a video from your iPhone to your TV, or if you want to watch YouTube on a larger screen, AirPlay, Apple’s casting feature, will help you do that. AirPlay allows you to wirelessly cast audio or video from your iPhone, iPad, or Mac to an Apple TV or an AirPlay 2-compatible smart TV, as long as your device is connected to the same Wi-Fi as the TV.
You can stream videos from any iPhone, iPad, iPod touch, or Mac. You can even stream video from a Windows PC, but only through iTunes. Just make sure your device’s operating system is relatively recent (a list of the various OS requirements can be found here).
With the latest version, AirPlay 2, you can also stream audio to multiple rooms, decide which room to play it in, and pair speakers. Here’s how to stream audio using AirPlay.