JPG 'JPEG' is especialy good and are used for realistic photographs but not for cartoon style images. They are not as good for high images such as print type images which are less realistic. JPG is typically used for realistic scenes on photographs and paintings and with smooth variations with tone and colour. Here is a classic example of an image using JPG photography .
GIF'GIF' stands for "Graphics Interchange Format". This format supports up to 8 bits per pixel and enables a single image to move and behave like a film/animation, they are used for images where more than one scene is needed to be shown, they behave in a way of a very short clip. This is an example of one.
PNG"PNG" stands for "portable network graphics" a
bitmapped image format that employs lossless data compression
. PNG was created to improve upon and replace GIF (Graphics Interchange Format) as an image-file format not requiring a patent license.
PNG supports palette-based ,greyscale, RGB, or RGBA images. PNG was designed for transferring images on the Internet, not professional graphics, and so does not support other colour spaces.