Timeline - displays a chronological order of events, from the earliest to the most recent.
Timeline Panel - Where you control the images and sounds in your flash document. Objects for animation are contained in layers on the timeline panel.
Frames - Are numbered in five-frame intervals.
Keyframe - is a frame where a new symbol instance appears in the Timeline. It may also include the ActionScript or the program you make on your Flash content.
Blank Keyframe - is a placeholder for symbols you plan to add later or just to leave the frame blank.