Digital device and method of processing video data thereof

In this specification, the various embodiment (s) of the digital device and a service processing method in the digital device is disclosed. Here, the digital device in accordance with one embodiment of the present invention, if a plurality of applications in the foreground, the first application with each of the first life-cycle message to each of the Web kit of the second application and the second lifecycle message and the the LSM transmitting the coordinate information on the size and position within the display of the second application; The display engine with the sub-sink for the main sink and the second application for the first application; And wherein in accordance with the identifier and the connect request is received connected to the first application in accordance with the identifier and the connect request is received from the web kit of the first application and the main sync of the display engine, and from the web kit of the second application, a second application, including the VSM to connect with the sub-sync of the display engine and outputs the video source of the plurality of the application in the foreground.