A display apparatus is provided. The display apparatus includes a first receiver, a display unit, a controller and a processor. The first receiver receives a network packet stream. The controller selectively sends one of a video signal generated by processing the network packet stream and an external video signal to the display unit for displaying the received video signal, according to a control signal. The processor determines whether the network packet stream comprises a display command. The processor sends the control signal to the controller for receiving and sending the video signal of the network packet stream to the display unit, when the network packet stream includes the display command.