I/O Management
Much of the OS kernel is concerned with I/O.
The OS provides a standard interface between programs (user or sytem) and devices.
Device drivers are the processes responsible for each device type. A driver encapsulates device-specific knowledge, e.g., for device initiation and control, interrupt handling, and errors.
There may be a process for each device, or even for each I/O request, depending on the particular OS.