Casts: A collection of members that can belong to a movie.

Cast members: Images, sound effects, drawings and so on. Loaded in to a bucket of assets which can then be referenced from the movie.

Cast members can be stored internal or external to a movie. Basically whether the asset is enclosed in the clip when compiled, or has to be kept nearby for playback. External clips are useful for intermediary movies being built up for the final movie to be exported, or situations like games where many movies share content.

Score: Shockwave's definition of a linear timeline. Each lane in the score is called a "channel."

Sprite paths: Tool that shows how sprites move across the stage in a movie.

Film loops: Entire movies can be condensed down to clips (which in turn become "cast members") which can be summoned up on a new movie with its own "score" (timeline.) So smaller animation clips can be used to build up a larger scene, keeping all of the animation layers and business going on somewhat manageable.

Behavior: Scripts, basically, that you can stick on cast members on a stage and it will run automatically. These have triggers such as once per frame or when the mouse enters or exits the clip's bounding box.

Step recording: Where you have to go to a frame, make a change, and the whole sprite status is keyframed there.

Tweening: taking a start and end state of a member on the stage, automatically transitioning some parameters from the start and stop copy, subject to some easing and smoothing of the parameters.

Scores

Cast members show up on the score to indicate when they are on the stage; presumably this also manages any tweening and keyframes for things which need to be animated in some way.

Markers: You can put markers on a particular frame number to keep track of what is supposed to be going on at that point