Cortana is a digital personal assistant created by Microsoft for Windows Phone 8.1, Microsoft Band, Windows 10 and the Xbox One. Cortana was demonstrated for the first time at the Microsoft BUILD Developer Conference (April 2–4, 2014) in San Francisco. It has been launched as a key ingredient of Microsoft’s planned “makeover” of the future operating systems for Windows Phone and Windows. It is named after Cortana, a synthetic intelligence character in Microsoft’s Halo video game franchise originating in Bungie folklore, with Jen Taylor, the character’s voice actress, returning to voice the personal assistant’s US-specific version Microsoft stated: You will also see a few differences between what Cortana can do today in her “native” environment (Windows) and in the app on Android. For example toggling settings, opening apps or invoking Cortana hands-free by saying “Hey Cortana” are only available on Windows for now. As with all betas, we are continually improving the experience and will incorporate feedback along the way. New users will have to go to this link on the Google Play Store and agree to the terms of the testing program before they can download the Cortana public beta. Source: Microsoft