A movieclip is a symbol with a timeline, just like the main timeline.
The timeline of a movieclip can contain buttons, graphics, and/or other movieclips
If a movieclip in a movieclip has a timeline, this timeline plays independently of the timeline it's running in.
Suppose a movieclip has a timeline with 20 frames, and a movieclip in this timeline has a timeline with 40 frames, and the last frame of this timeline shows a red dot. This dot is seen every second time the 20 frames long timeline animates.
The properties of a movieclip, like size, alpha value (transparency), dimension, and position, can be adjusted by selecting the movieclip on the stage. As soon as a movieclip is selected, the Movieclip Properties window is shown (see image).
ActionScript can also be used to change the properties of a movieclip.
The 'Up' state shows the default state of the button and/or the state when a user releases the button. The 'over' state is the frame which is shown as soon as a user moves over the button with the mouse. The 'down' frame shows the state of the button when a user clicks on the button.
The 'hit' state is not a visual state, but describes the area which the mouse detects to trigger one of the three possible states. Usually this is a plain rectangle and the size is the same as that of the other states.
A graphic can be used for static content, such as bitmap images or vector images.
Like the movieclip, a graphic has a timeline, so that animation is also an option.
Unlike the movieclip, the timeline of a graphic doesn't run independently of its possible predecessor(s).
If the timeline of a movieclip with 20 frames contains a graphic with a timeline of 40 frames, and the last frame of the timeline of the graphic has a red dot, the red dot will never show up, since only the first 20 frames of the graphic will be shown.