Noun

Singular device driver

Plural device drivers

device driver (plural device drivers)

1. (computing) software, supplied with the operating system or by a hardware manufacturer, that communicates between the operating system of a personal computer and a specific hardware device

In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device.

A driver typically communicates with the device through the computer bus or communications subsystem to which the hardware is connected. When a calling program invokes a routine in the driver, the driver issues commands to the device. Once the device sends data back to the driver, the driver may invoke routines in the original calling program. Drivers are hardware-dependent and operating-system-specific. They usually provide the interrupt handling required for any necessary asynchronous time-dependent hardware interface.

Purpose

A device driver simplifies programming by acting as an abstraction layer between a hardware device and the applications or operating systems that use it. The higher-level application code can be written independently of whatever specific hardware device it will ultimately control, as it can interface with it in a standard way, regardless of the underlying hardware. Every version of a device, such as a printer, requires its own hardware-specific specialized commands. In contrast, most applications utilize devices (such as sending a file to a printer) by means of high-level device-generic commands such as PRINTLN (print a line). The device-driver accepts these generic high-level commands and breaks them into a series of low-level device-specific commands as required by the device being driven. Furthermore, drivers can provide a level of security as they can run in kernel-mode, thereby protecting the operating system from applications running in user-mode.