Overview
WIA is a significant superset of the support for digital still imaging drivers that was provided by the Still Image Architecture (STI) in Windows 98. Whereas STI only provided a low-level interface for doing basic transfers of data to and from the device (as well as the invocation of an image scan process on the Windows machine through the external device), WIA provides a framework through which a device can present its unique capabilities to the operating system, and applications can invoke those features. According to Microsoft, WIA drivers are made up of a user interface (UI) component and a driver core component, loaded into two different process spaces: UI in the application space and the driver core in the WIA service space.
Many scanners support WIA.
Read more about this topic: Windows Image Acquisition