Definitions of editing rules

Explaining the following aspects of continuity editing.

180° rule

The 180° rule is a basic film editing guideline that states that two characters in the same scene should always have the same left/right relationship to each other. If the camera passes over this imaginary axis connecting the two subjects, it is called crossing the line. The new shot, from the opposite side, is known as a reverse angle and does not always match correctly and may confuse the viewer.

http://uk.youtube.com/watch?v=fMq8t0d3gLE

Match on action

Match on action is a technique used in film editing it is a cut that connects two different views of the same action at the same moment in the movement on screen. This is done by carefully matching the movement across the two shots, filmmakers make it seem that the motion continues uninterrupted. For a real match on action, the action should begin in the first shot and end in the second shot.

http://uk.youtube.com/watch?v=BRRavGgX1pw