First of all, to function productively in Flash, we need to understand the metaphor that Macromedia has adopted for the program.
Consider Flash to be a production house where you would go to create movies. When you first walk in the door of this production house (ala open the program), you'll see 3 general areas of importance:
Forgetting the metaphors for a minute, you need to learn about the program's functions in the order just given, so that when it comes time to 'shoot' your movie, you won't be confused about what goes where and why this happens instead of that. We're going to start off understanding the TimeLine area first.
"Time Is A Linear Concept"
Scenes:
Just like real movies, Flash can combine multiple "Scenes" to create a full length movie. When the program opens, you'll be working in "Scene 1". And you can add as many as you'd like. In Flash, think of Scenes as individual segments of the movie. Like when you're watching a TV movie and the scene cuts from an indoor shot, to a guy in a boat on a lake. Those would be two different scenes in the movie. Both shot at different times, on different locations, and using different props or actors. Having this ability makes the program very versitile when creating an entire Web site from a Flash movie. The individual scenes could be separate pages or areas within the site.
It is not essential to use multiple scenes in a movie. For a simple "intro" movie, one scene will do.
Layers:
By default, when the program starts you'll get one single layer to work on. Think of the layers in Flash as overhead projector transparencies. You can either put a single pixel dot on it, or fill the layer completely until the backdrop is no longer visible. If you created 4 layers, each having a single object on them, then because the layers are in essence transparent, all objects will be visible at all times, if left uneffected.
Anyone who's worked with Photoshop, Illustrator, PaintShop Pro, etc., will understand how layers work. In general, Flash treates layers the same way these other graphics programs do. The only difference with Flash is that each of its layers also has its own linear motion timeline as well.
Frames:
The general concept of a timeline is easy to understand - you live in one every day. When looking at Flash's Timeline area (the small blocks running left-to-right beside the Layer names), simply think of each small block as a moment in time. For film, these small blocks of time are known as frames. Not unlike the frames you've seen on a movie film reel. All Flash has done is to 'unroll' the reel and lay it out in a linear fashion from left to right.
Key Frames:
In acting, they use something called a "mark". It's usually a small spot on a stage or set that has been "marked" off. Sometimes they'll even put an actual visual mark on the spot, such as a small X of red tape. The idea of the mark is to cue the actors and camera people to where they should be at a given moment in time, so that a change can take place in the scene. I'm sure you've heard this saying in the movies or on TV, "You missed your mark", or "This will be your mark".
In Flash, a "mark" is known as a "Keyframe" and serves the same purpose. This is the small block in time (1 frame) where a major change takes place within your movie scene. Keyframes are usually used to setup some special effect, such as morphing, alpha blending, a change in scenery, or motion.
Another use for a keyframe is when you want to change everything on the stage and start a new section in your movie, with a new cast of objects. But Flash 'Scenes' can also be used for that specific function.
See Tips for more on converting a normal frame into a Keyframe:
