Snap is a feature that lets users run two applications at one time. For example, a user could be watching a sports program on the ESPN app and want to check out players' stats while still watching. With Snap and Kinect voice command, the user can do just that by opening up another window and checking out the stats.
This function opens up many possibilities when it comes to gaming as well. You could, for example, have the game running on the left side of the screen and a web browser open on the right hand side of the screen with a guide to the game you're playing.