It's hard to believe that something so basic to animation had its start with Lego blocks, but the software we now know as Flash traces its roots to that constructive toy. In this article, you'll get an overview of the tools you can use in Flash CS3 Professional, and learn how to navigate its toolbars and windows.
Flash: Building Blocks - The Staging Area (Page 2 of 4 )
The stage, simply put, is where all the action takes place. It is where the animations get down and party while the buttons sit on the side and act like wallflowers. Anything within this space will be viewed by the user; the area to the left and right will not be viewed. Consider it the backstage area.
The backstage area is sometimes a useful place to store objects, though I would not recommend making a habit out of it; while they aren't supposed to, objects left in this area have a funny way of leaping onto the stage when you don't want them to. It's rather like those people you see on the news, waving in the background behind the reporters.
Timeline
The timeline allows the user to set his animation in flow. The easiest way to think of a timeline is to envision a movie reel laid out flat, frame by frame. If the movie was a man walking, each frame would show his feet lifting off the ground into a higher position and then gradually falling as he moved forward.
In addition to holding frames, the timeline can also hold actions and triggers for other movies. Your Oscar-winning web animation of a man walking might decide to have him jump when the movie reaches the one-hundredth frame. I know -- watching a stranger walk is sure to pack them into the theaters; but adding that jump will keep them talking about your movie for days.
You'll also note that the Timeline section contains your Layers, which will be discussed in later chapters. For now, just be content to know that you can find them here.
Flash 
Advanced Flash Animation
