The adapter is a dongle that plugs into the TV's HDMI port; a cable connects to a USB port to power the device. A mobile app makes it possible to essentially use a smartphone, tablet, laptop or desktop computer as a TV remote. Once the streaming begins, it's not necessary to keep the app open, and the device can be used for other purposes. Chromecast can stream content from an increasing number of sources including Netflix, Hulu Plus, YouTube, Google Play music and movies and the Chrome browser.
Chromecast competes with other devices for streaming media to the television including Roku's Streaming Stick and Apple TV.
See a Chromecast walk-through and review: