Dolby Atmos gets a lot of attention for its ability to reproduce sound from a lot of speakers, including those that come from above. What's more important is to understand the new approach used in that process. This new approach uses a concept known as objects. An object is essentially a channel of audio that also contains information representing its position in space as an X, Y and Z coordinate. This positional information, known as metadata, is carried with the object from the time of its creation all the way to the point of consumption. It's the Z axis that provides the opportunity to place the sound above the listener by utilizing speakers placed on the ceiling to create an immersive experience not present in legacy surround sound formats. 

Take a moment to see the general idea behind object-oriented audio:

Dolby introduced object-oriented mixing with the film Brave, released in 2012. Since that time Dolby Atmos has become a premium standard in commercial cinema. People have always desired to take the cinema experience home and Dolby has now provided the pathway to do just that. Dolby Atmos home theaters are a reality. To go a step further it's even possible to derive a Dolby Atmos object-based experience on mobile devices over conventional headphones. 

To accommodate such a wide variety of listening environments using a wide variety of technologies, Dolby has needed to create an equally wide variety of tools to allow for the creation, transportation, and consumption of Dolby Atmos mixes.