Smart phone/tablet computer displayable and operable on front and rear sides or multiple sides

A front-and-rear-side or multiple-side displayable and operable smart phone/tablet computer, comprising a main body, which has a front side and a rear side respectively provided with a first displaying/operating unit and a second displaying/operating unit, and a control unit, which is arranged inside the main body and electrically connected to the first displaying/operating unit and the second displaying/operating unit for transmission of a signal and switching the first displaying/operating unit and the second displaying/operating unit between a synchronous display mode and a non-synchronous display mode, the non-synchronous display mode being such that the first displaying/operating unit and the second displaying/operating unit individually display a signal in processing and the synchronous display mode being such that the first displaying/operating unit and the second displaying/operating unit synchronously display a signal in processing, characterized in that the control unit is further electrically connected, in a detachable manner, to at least one third displaying/operating unit and the control unit further comprises an image processing section, wherein the signal, after being processed by the image processing section, enables the first displaying/operating unit, the second displaying/operating unit, and the third displaying/operating unit to individually display one of a color signal and a grey-scale signal.