Chromecast is an HDMI dongle sold by Google that allows users to broadcast the screen of another device to a television set. It was released on July 24, 2013.
After connecting the Chromecast to a television set or monitor, supported devices (including laptops, computers, Smartphones, and Tablets) can broadcast their screen over Wi-Fi. Websites such as HBO, YouTube, and Netflix can broadcast their videos directly to the Chromecast, and more apps that support the Google Cast technology are also in development.
The Chromecast is unique from similar products because it is only $35 and can stream any Chrome browser tab to any TV, which means you can watch anything you can open on your browser.
Also see: Android, Video terms