Final answer:
An I/O controller is an I/O module that presents a high-level interface to the processor and takes on most of the detailed processing burden.
Step-by-step explanation:
An I/O controller is an I/O module that takes on most of the detailed processing burden, presenting a high-level interface to the processor. It is responsible for controlling the flow of data between the processor and the various input/output devices. The I/O controller manages the communication protocols, data translation, and data buffering, allowing the processor to interact with the devices at a higher level of abstraction.
In computing, an I/O controller is responsible for managing the interface between the computing system's processor and the external devices. This includes handling the details of input/output operations, such as data transfer, signaling, and error handling. The I/O controller often contains the logic to deal with the specific protocols and signals of different I/O devices, freeing up the CPU to perform other tasks. The other options listed, such as I/O channel, I/O command, and device controller, are related concepts but do not specifically describe an I/O module focused on processing burden reduction.