Host device and input-output system

A host device comprising:

• a display device that, in operation, displays an image in a host display region;
• a communication device that, in operation, communicates with multiple guest devices each having a display function;
• and
• a processor that, in operation, divides the host display region into at least two sub-regions and controls the display device to display at least two images currently displayed by at least two of the guest devices simultaneously connected to the host device, such that the at least two images are respectively displayed in corresponding ones of the at least two sub-regions,
• wherein the processor, in operation, selectively gives an execution right to a first one of the at least two of the guest devices,
• wherein the execution right enables the first one of the at least two of the guest devices to remotely execute a graphical user interface operation on the display device of the host device,
• wherein, in response to receiving the graphical user interface operation from the first one of the at least two of the guest devices to which the processor has given the execution right, the processor performs the graphical user interface operation on the display device of the host device,
• wherein the graphical user interface operation is a drag and drop operation that moves an icon in a first sub-region corresponding to the first one of the at least two of the guest devices into a second sub-region corresponding to a second one of the at least two of the guest devices, and
• wherein, when accepting the drag and drop operation from the first one of the at least two of the guest devices, the processor changes the host display region of the display device based on the drag and drop operation and transfers a data file corresponding to the icon from the first one of the at least two of the guest devices to the second one of the at least two of the guest devices via the communication device.