Like the PlayStation 4, the Xbox One will also let you play games while they are still being downloaded to the console.
We knew for a while now that the Xbox One would allow users to play disc-based games while they're installing to the system's hard drive; installing disc-based titles is a requirement on the Xbox One. It was unclear, however, if this same functionality would also apply to digital games that are downloaded from Xbox LIVE.
As previously mentioned, the PS4 also allows users to begin playing a game when it reaches a certain point in the download. Similarly, the PS4 will also allow you play a disc-based game as it's being installed to the hard drive, essentially removing those lengthy installs that plagued the PlayStation 3.