Logical Screen Descriptor has the following information.

☛ - Logical Screen Width: The width of the image that represents in pixels

☛ - Logical Screen Height: The image height in pixels.

☛ - Packed Field: The element of the image for animation.

☛ - Background Color Index: A value that is pointing to a color in the Global Color Table.

☛ - Pixel Aspect Ratio: The approximate aspect ratio of the pixel in the GIF image