180 degree rule
The 180-degree rule is a guideline regarding the on-screen position between a character and another character or object within a scene. The axis runs between the characters and by keeping the camera on one side of this axis for every shot in the scene, the first character will always be to the right of the shots position, while the second will always be to the left of the shots position to avoid disorientating the audience.
this rule should also apply to a character or object moving, for example, if a man was walking and being filmed from the left side and so walked off frame to the left , the man should come back onto frame in the next shot from the right and continue to be filmed from the left. this always applies unless the director wishes to create a sense of time passed between shots.
In a dialogue scene between two characters the camera may be placed anywhere on the green 180° arc without disorientating the audience even when one of the characters is not on screen. Shifting to the other side of the characters on a cut, so that the two men have switched positions may disorient the audience.
shot reverse shot
Shot reverse shot is when one character is shown looking at another character ,and then the other character is shown looking back at the first character. Since the characters are shown facing in opposite directions, the viewer assumes that they are looking at each other.
Match on action
Matching on action is where the editor cuts from one shot to another view that matches the first shot's action. Matching on action gives the impression of continuous time when watching the edited film by having a charicter or object begin an action in one shot and carry it through to completion in the next .