What is the name of a shot that is related to the main shot and is used to support the main shot?

The correct answer is the cutaway shot. A cutaway is used to provide additional context or information related to the primary shot, enhancing the audience's understanding of the scene. It often depicts something that is not in the main shot, such as a character’s reaction, an object, or an environment that is connected to the action taking place. By inserting a cutaway, filmmakers can guide the audience's focus, create a smoother flow of the narrative, and add emotional depth or tension to the story.

In contrast, a reaction shot primarily captures a character's response to something occurring outside the frame of the main shot, rather than supporting it with additional context. An establishing shot sets the scene and provides viewers with a clear understanding of the setting but does not directly support the main shot as a cutaway does. An over-the-shoulder shot focuses on the perspective of one character, usually during dialogue, but it serves a different purpose by emphasizing the interaction between characters rather than providing supplementary information related to the main shot.