☛ - GIF file has fixed size graphical area.

☛ - It contains one or more images.

☛ - Every image can be animated by placing them in animation frames.

☛ - Every part of GIF file is a frame.

☛ - All such frames make the complete graphical area or logical screen.

☛ - Every file starts with a fixed length header.

☛ - Every logical area consists of an image, the extension block and the trailer that is referred as the last byte of the file.