One of the appealing features that Windows 8.1 Preview was made available with was support for a wider range of devices, through several new and innovative APIs included in the platform release.

Windows 8 already offered support for various device scenarios, including print, sensors, and geolocation, but provided limited access to arbitrary devices (available only for dedicated device apps).

Windows 8.1 Preview, however, changes that, as support for APIs such as Point of Sale (POS), 3D printing, and scanning is included in the new platform release.
Microsoft Details Windows 8.1