Microsoft's Xbox One will use Blu-ray discs for games, but you won't be using them as frequently as you might have with your PlayStation 3. In a statement made to Wired, Microsoft said that all games are installed to the Xbox One's hard drive to play; you won't have to insert the disc to run the game after that initial process. The news confirms earlier information seen by The Verge.
Prior to the Xbox One's official unveiling, rumors had flown for months that Microsoft's latest console would contain a mechanism to block used games. While Microsoft has so far stayed quiet on this particular point, the mandatory installation would seem to suggest that there may have been at least some truth to the reports.

Microsoft will charge fee for secondary installation
Microsoft has said that a fee will be charged for any game disc to be tied to a second Xbox Live account after its initial installation. This is likely to limit the market for second-hand games, but would not eliminate the possibility altogether. The company is yet to confirm whether players will be able to play games from disc or run them on secondary accounts without paying for the installation, nor has it given any indication of what the fee may be.
As for the rumors that claimed the Xbox One would require a constant online connection to run games, Wired says the reality is not as overbearing. Developers will be able to create games that hook into Microsoft's Azure cloud services and are unable to be played offline, but there is as yet no requirement for them to do so