Extreme Close-up

 A shot taken very close to the subject (closer than would be necessary for a close-up), revealing extreme detail, e.g. part of the human face. I'ts a very tight framing method that shows only a tiny part of the subject in great detail. On a person, usually this is the face or the eyes, and on an object this tends to be a small portion showing an element or piece of it.

Continuity

Most of the time, we think of continuity as showing something that simply "continues on the same path".  

 The defintion of continuity is a motion picture scenario giving the complete action and scenes in detail and in the order in which they are then shown on the screen.

180 degree rule

The 180 degree rule is as filming guideline that participants in a scene should have the same left-right relationship to each other, with filming only taking place within the 180 degree angle in which this is maintained in a conversation for example.

For example in King Vidor's The Big Parade (1925), the audience's viewpoint is constantly southward of the action- the American soldiers walk from left to right to the front-lines, and right to left when they return home, creating a continuous sense of direction.

This allows the audience to have a greater sense of location in the scene in terms on what may be off-screen in some shots, for example in shot reverse shots.

Shot/reverse shot

Shot reverse shot is a continuity editing technique used in conversations or simply characters looking at each other or objects.

A shot showing what the character is supposedly looking at (either a point of view or over the shoulder shot) is followed by a reverse angle show of the character themselves looking at it, or of the other character looking back at them, for example.

Shot reverse shot often ties in with the 180 rule to retain continuity by not distorting the audience's sense of location of the characters in the shots.