A higher-level driver that typically provides hardware-independent support for a class of physical devices. A class driver generally communicates with a lower-level miniclass driver or port driver, using a combination of device I/O control requests ( IOCTLs), callbacks, and support routines. The system supplies class drivers for keyboard, mouse, and storage devices, among others. For more information see the topic, Layered Driver Architecture. See also, descriptions of device-specific technologies in this documentation.
A driver that provides system-required, hardware-independent support for a given class of physical devices. Such a driver communicates with a corresponding hardware-dependent port driver, using a set of system-defined device control requests, possibly with additional driver-defined device control requests. Under WDM, the class driver creates a device object to represent each adapter registered by minidrivers. The class driver is responsible for multiprocessor and interrupt synchronization.
A driver, usually written by Microsoft, which generically controls devices of a certain class. For instance, cdrom.sys controls all CD ROM drives on the machine. Typically a class driver exists at a level of abstraction above the hardware. In this example, cdrom.sys uses SRBs to communicate with the CD ROM drive instance, the PDO for the CD ROM driver translates the SRBs into bus specific commands.