Image file that may contain up to 256 indexed colors; color palette may be a predefined set of colors or may be adapted to the colors in the image; lossless format, meaning the clarity of the image is not compromised with GIF compression.
GIFs are common format for Web graphics, especially small images and images that contain text, such as navigation buttons. However, JPEG (.JPG) images are better for showing photos because they are not limited in the number of colors they can display.
GIF images can also be animated and saved as "animated GIFs," which are often used to display basic animations on websites. They may also include transparent pixels, which allow them to blend with different color backgrounds. However, pixels in a GIF image must be either fully transparent or fully opaque, so the transparency cannot be faded like a .PNG image.
View the GIF definition.