Method for outputting image data from terminal to display device and terminal thereof

A video transmission method in the source terminal to the external display device connected to the source terminal, the method comprising: at said source station, detecting a connection with the external display device; Identifying a video source to be transmitted to the external display device; And a video transmission method comprising: transmitting from said source terminal to the external display device, the image data related to the identified video source through a video output interface is provided.