Definition - What does Device Driver mean?
A device driver is a particular form of software application that is designed to enable interaction with hardware devices. Without the required device driver, the corresponding hardware device fails to work.
A device driver usually communicates with the hardware by means of the communications subsystem or computer bus to which the hardware is connected. Device drivers are operating system-specific and hardware-dependent. A device driver acts as a translator between the hardware device and the programs or operating systems that use it.
A device driver may also be called a software driver.
Techopedia explains Device Driver
The sole purpose of a device driver is to instruct a computer on how to communicate with the input/output device (I/O) by translating the operating system's I/O instructions into a language that a device can understand. There are various types of device drivers for I/O devices such as keyboards, mice, CD/DVD drives, controllers, printers, graphics cards and ports.
There are also virtual device drivers (VxD), which are device driver components that enable direct communication between a hardware device and an application. Virtual device drivers help to manage the data flow to enable multiple applications to access the same hardware without a conflict. When there is an interrupt (a signal from a hardware device), the virtual device driver configures the next instruction step based on the status of the hardware device settings.
It is essential that a computer have the correct device drivers for all its parts to keep the system running efficiently. When first turning on a computer, the OS works with device drivers and the basic input/output system (BIOS) to perform hardware tasks. Without a device driver, the OS would not be able to communicate with the I/O device.
Not only do physical hardware devices rely on a device driver to function, but software components do as well. Most programs access devices by using general commands; the device driver translates the language into specialized commands for the device.
Many device drivers are provided by the manufacturer or are available as built-in components of the OS. When hardware and software components are updated or replaced, this renders the device drivers obsolete.