You can use AirPlay on an iPad to mirror your tablet's screen or stream content to a larger display, like your TV.
You can mirror your iPhone screen to a TV or Mac computer in several ways, including a hardwire connection or by using AirPlay.
You've got a video on your iPhone and a computer across the room. Can you quickly show the video on it? If the computer in question is a Mac, yes—just use AirPlay ...