The 180 degree rule

The 180 degree rule is a guideline used in film making. the main purpose of this rule is to keep the audience orientated as to where everything is in the scene. In a conversation a line between the two actors will be drawn straight across them. All camera must remain on one side of the 180 degrees to ensure the actors are facing each other in the conversation and remain on the same side of the scene. The first character is always frame right of the second character, who is frame left of the first. The camera jumping over the line is called jumping the line.