CCD The main concept CCD or Charge Coupled Device is based on the fact that a CCD shows photoelectric effect when light falls on it. The charge acquired by a two dimensional array of capacitors are transferred a charge amplifier when light of the captured scene falls on it. The charge amplifier converts the charge into voltage. By repeating the process the whole image is captured and transferred to the next stage for further processing.

CMOS or Complementary Metal Oxide Semiconductor Sensors are created using the same manufacturing technology which are used to make microprocessors. These chips contain transistors at each pixel position which amplifies and moves the charge using more conventional wires which is a more flexible technology as every pixel can be read individually.