A display device is disclosed. The display device includes a display, a communication interface comprising circuitry, a storage configured to store combined information on contents available from a plurality of input sources, and a processor configured to control the communication interface to receive an external input signal from the plurality of input sources, display, through the display, recommendation information on a content available through a first input source from among the plurality of input sources based on a viewing history of a user and the combined information stored in the storage, the viewing history of the user is a viewing history related to an external input signal provided through a second input source from among the plurality of input sources.