A charge-coupled device (CCD) is a light-sensitive integrated circuit that captures images by converting photons to electrons.
A touch screen is a computer display screen that is also an input device. The screens are sensitive to pressure; a user interacts with the computer by touching pictures or words on the screen.
The similarity is the sensitivity. The difference is CCD scans or ‘takes images’, whereas touch-screen is where a user interacts with the software.