Using the Windows:

The Stage and the Timeline window:
As with film, Flash movies divide lengths of time into frames. The Stage is where you compose individual frames in the movie, drawing directly on it or arranging imported artwork. The Timeline window is where you coordinate the timing of the animation and assemble the artwork on separate layers. The Timeline window displays each frame in the movie. Layers act like a stack of transparent acetate, keeping artwork separate so you can combine different elements into a cohesive visual image.

The Library window:
The Library window is where you store and organize symbols created in Flash, as well as imported files including sound files, bitmap graphics, and QuickTime movies. Symbols can consist of graphics, buttons, or movie clips. The Library window lets you organize library items in folders, see how often an item is used in a movie, and sort items by type.