is a technique where the camera betrays an object or talent by leaving it behind with nothing prominent to replace them.
Pull back and reveal,
is a technique of movement. The camera moves backwards revealing more information. It may be an object, character, or the backdrop.
or push-in, is when the camera approaches its subject. Often the the character is first framed in a wide view before the approaching. The camera can close in slowly for an emotional effect or quickly for an exciting effect. It is a substitute for zoom or a match-cut for a specific purpose at the decision of the director.
The Camera Dolly, may have variations following its subject or leading them. When the camera trails the subjects, the audience has a view where they are going as if they were an uncounted member of the group. Sometimes, we want to capture the reactions by leading them. Instead of seeing where they are going, we see where they have been. A slight, subtle, but effective differences between the two.
The Camera Dolly, Reveal in Background is a technique introducing a new subject, generally from the left or right edge as the camera travels horizontally as the new subject appears in the background. The shift in focus is more subtle than the variation reveal in foreground. The separation of depth may go unnoticed by the audience and is most effective as subconscious messaging or a method of foreshadowing.