Answer:
Image is the copy of the principle object. The image can be 2D or 3D . A 2D image will have only 2 axis that is the X axis and Y axis, eg is the radiograph in which the vertical and horizontal components are visible. While in a 3D image along with X and Y axis the 3 rd component Z axis is visible . In a 3D image the depth axis is included, eg is animated vedios.