Question

What term describes what an actor breaks when he addresses the audience directly from stage, like in Hamlet’s “to be or not to be” soliloquy

Answer 1

breaking of the third wall.
if you were to be an actor on a stage and directly ask the audience a question, or making a statement that you as a character acknowledge that the character knows it is a play.

Answer 2

When the actor is on stage and addresses the audience directly, it is called breaking the Fourth wall. This term is used to describe the invisible or the imaginary wall between the audience and the actors on stage. In a proscenium theater , the set is usually three walls of a room. The audience is therefore the fourth wall and normally ignored by the actors. The audience can obviously see through this wall but the convention assumes the actors act as if they cannot. The same also happens in movies, only that the fourth wall is the camera lens.