The Xbox One is receiving an update that allows the console to stream games to Windows 10 PCs once the operating system launches on July 29. The update also sets the console up for backward compatibility, through which you can play Xbox 360 titles on the Xbox One.
Microsoft has mentioned during its E3 2015 conference that the feature works by integrating an Xbox 360 emulator into the Xbox One. The hardware giant announced the first 21 games that preview users can play, with over 100 titles set to be available once the feature formally launches this holiday season.
Source: Major Nelson