According to one embodiment, a communication system includes a video signal receiver, a video signal output module, a power control signal receiver, and a socket. The video signal receiver is configured to receive a video signal from a first external apparatus. The video signal output module is configured to output, to a second external apparatus, the video signal received from the first external apparatus. The power control signal receiver is configured to receive a power control from the first external apparatus. The power control signal receiver is lower in power consumption than the video signal receiver. A power cable configured to supply power to the second external apparatus is connected to the socket. When the power control signal receiver receives a power control signal for activation, power is supplied to the video signal receiver and the socket.