AirPlay is Apple's Wi-Fi content-streaming technology that enables you to push music and video from your iDevice to your television, with Apple TV ($99) as the wireless intermediary that makes it happen. Since I've owned an Apple TV, I've streamed photos, videos, and music from my iPhone to my TV. For instance, I take a bunch of photos of my kids playing outside and later, when we're inside, I flash those photos quickly on my TV. Wirelessly. Simply.