What does the OS use to interact with hardware devices?

The operating system (OS) utilizes a device driver to interact with hardware devices. A device driver is a specific type of software that acts as an intermediary between the operating system and hardware devices. It provides the necessary interface for the OS to communicate with hardware components, ensuring that the system can correctly control and utilize various peripherals, such as printers, graphics cards, and network adapters.

When an application needs to use a hardware device, it sends requests through the OS, which then relays those requests to the appropriate device driver. The driver converts these requests into commands that the hardware can understand, enabling smooth interaction and operation.

In this context, other options have distinct roles but do not serve the same function as a device driver. Firmware refers to low-level software programmed directly into the hardware that provides control and functionality. System calls are standardized interfaces through which applications request services from the OS. Kernel modules are pieces of code that can be loaded and unloaded into the kernel on demand, often used for device drivers or adding functionality to the OS. While all these elements play essential roles in system operations, it is the device driver specifically that enables the OS to communicate directly with hardware elements.