Photo editing is the changing of images. These images can be digital photographs, illustrations, prints, or photographs on film). Some types of editing, such as airbrushing, are done by hand and others are done using photo editing programs like Photoshop, Gimp and noise reduction. Photo editing is done for many reasons. Many photos of models are edited to remove blemishes or make the model "better". This is usually called retouching, airbrushing or Photoshopping, even if Photoshop or airbrushes are not used. Other reasons to edit a photo include fixing errors (red eye, contrast, brightness, etc.), practical jokes, and to trick people. Photo editing is also used to make completely new images. Photo editing is sometimes called photo manipulation, usually when it is used to trick people.