The Background Color is the color used to paint the animation bounding box where no frame is displayed. With some Web browsers, the page background is used instead. The Loop option specifies how many times the animation is repeated. Some browsers don't recognize this option, while others loop an unlimited number of times if the setting is more than 1. The Frame Position specifies the horizontal and vertical distances between the top left animation corner and the top left frame corner.
Positive values push the frame to the left and to the lower part.
Negative values result in a cropped frame. The Interframe Delay is the delay between the current frame and the following frame renderings. The Disposal Method specifies what each frame becomes once the interframe delay is elapsed. Do Not Dispose when you want to add some bits of image to the previous animation state, Revert to Background for moving objects on a transparent background, and Revert to Previous for moving objects on a background you've drawn with an earlier large frame. Note that Revert to Background isn't supported by some browsers.