Default Frame Rate
The default frame rate that is displayed in the Controller Palette is set here. By default it is 10 frames per second (fps), but you can set it to any value you like.
Default GIF Export Frame Delay
The first time you export your animation to the Animated GIF format, the default value used in the Export Animated GIF window comes from this preference. By default it is set to 6/100ths of a second delay, but you can set it to any value you like, although values under 6/100ths are less compatible with existing web browsers. (See the About the Animated GIF Format topic for more information.)