AirPlay (formerly called AirTunes) is Apple's technology for streaming media over a local (usually in-home) network. It lets you stream audio from any Mac or iOS device to any AirPlay-enabled audio system, or video from a Mac (of recent vintage) or an iOS device to an Apple TV (also of recent vintage).

AirPlay works over any modern ethernet or Wi-Fi network (for video over Wi-Fi, that ideally means a fast network using 802.11n technology). The sending and receiving devices also need to be compatible with AirPlay.

How you set up and use AirPlay depends on the devices involved and on whether you're streaming audio or video. Here's how you can get up and running.

(Note that these instructions assume AirPlay and your local network are working correctly. If not, Apple provides AirPlay troubleshooting information).

The basics

At its simplest, AirPlay is a convenient way to get audio from your Mac or iOS device to a speaker across the room--or across the house.

Though most people think of AirPlay as a wireless technology, you can also stream audio over a wired network, or between wired and wireless devices--for example, from an iPhone to an ethernet-connected AirPlay receiver. But AirPlay is also a relatively inexpensive way to set up a whole-home audio system--at least when compared with a custom-installed setup or something like a multiroom Sonos system.

Compared with Bluetooth