180 degree shot

180 degree rule

In film making, the 180-degree rule is a basic guideline regarding the on-screen spatial relationship between a character and another character or object within a scene. An imaginary line called the axis connects the characters, and by keeping the camera on one side of this axis for every shot in the scene, the first character is always frame right of the second character, who is then always frame left of the first. The camera passing over the axis is called jumping the line or crossing the line.

The object that is being filmed must always remain in the centre, while the camera must always  face towards the object.

over the shoulder

shot of someone or something taken from the perspective or camera angle from the shoulder of another person. The back of the shoulder and head of this person is used to frame the image of whatever (or whomever) the camera is pointing toward. This type of shot is very common when two characters are having a discussion and will usually follow an establishing shot which helps the audience place the characters in their setting. It is an example of a camera angle.