What is the main purpose of device drivers?

Every hardware component connected to a computer, such as a printer, graphics card, or mouse, communicates using its own particular signals and commands. The operating system cannot understand these signals directly, so it needs a piece of system software, called a device driver, written specifically for that hardware device.

A device driver translates the general instructions the operating system sends into the exact commands the specific hardware understands, and it translates the responses from the hardware back into a form the operating system can use. This is what allows the operating system to detect, configure, and control a wide range of different hardware devices without needing to know the internal engineering details of each one. Running application programs is the role of the operating system working together with application software, not the specific role of a device driver, and device drivers do not provide internet security; that function belongs to security software such as firewalls or antivirus programs.

Examination reminder: whenever a question ties a piece of software to controlling or enabling a specific piece of hardware, the expected answer is a device driver.