A 180 degree line of action is the rule where there is an imaginary line which connects the characters and by keeping the camera on one side of the axis all the time in the scene. The character will always be frame right of the other character who is always on the left. if the camera crosses the line it will make the scene look stupid as the characters will have flipped.

A shot reverse shot is where one camera is shown looking at another character and the camera then shows the second character facing the character speaking. This shows that the characters are looking at each other.

A match on action is a simple but essential tenchique, where the perspective of the camera changes during a scene and the scene continues to flow









