What is rhetorical device

It is a technique that an author or speaker uses to convey to the listener or reader a meaning with the goal of persuading him or her towards considering a topic from a different perspective.

A rhetorical device is technique that an author or speaker uses to convey to listener or reader a meaning with the goal of persuading him or her towards considering a topic from a different perspective, using sentences designed to encourage or provoke a rational argument from an emotional display of a given perspective or action. Rhetorical devices can be used to evoke an emotional response in the audience, but that is not their primary purpose.