Loading and preloading
Note graphic symbols and mc are loaded before the movie starts playing. With larger file sizes it is best to load items when they are need in the animation. That is load them dynamically. That way the move is not waiting around loading content that it may no use until have way into the movie.

Basic preloaders
basic preloaders play a quick loading looped animation while components for the main movie are loading into the flash player. Simple actionscript is used to check if all the components have been fully loaded if they haven't the "loading" animation continues to loop. Once all the components have been loaded the movie then begins to play.

How to create the preloader animation loop
How to create a basic preloader

Basic preloaders with percent loaded display
Other types of basic preloaders can be made to display the percentage loaded. This can be used to dynamically control the preloader animation letting the user know the progress of the preloader.

How to create a basic preloader with percent loaded display
How to create a basic preloader with progress bar display

Dynamic staggered preloader
These preloaders "intelligently" load components for an animation sequence based on the order of appearance in the main move. This allows the movie to play before all the components have been loaded as the remaining components can be loaded as the movie plays reducing the preloading delay.

How to create an "intelligent" preloader