1. An electronic device, comprising: a camera configured to capture images; a display module configured to display images; and a controller configured to: acquire a first map image having map content, the map content corresponding to a specific area; extract a second map image from an external image received via the camera, the external image including a real map photographed via the camera, the photographed real map corresponding to the specific area, and the second map image corresponding to the photographed real map; synthesize the second map image and the first map image into a synthesized map image; and control the display module to display the synthesized map image.