The 180 Degree Rule

The rule is that you have to keep the camera on one side of the action. for example if two people are talking we can think of an imaginary line between them then the viewer can see one person is on the left and the other person is on the right. if you break the rule and put camera's on each side of the line then it will appear that the people are lookin towards the same direction while talking which will confuse the viewers and create misunderstandings.