An electronic device includes an imaging unit configured for capturing an image of a subject, a memory unit configured for storing data and images; a processing unit configured for processing data and images; a display unit configured for displaying data and images; and a central processing unit configured for processing various signals and images. The processing unit includes a replay module, a selection module, a function module, a menu module and an input/output unit. The input/output unit is configured for activating anyone of the replay module, the selection module, the function module and the menu module. The application system for the electronic device through activating each module via the input/output interface unit can allow the use of the electronic device to be more convenient and simplified.