Which term refers to the contrast between two very different things or ideas?

The term that refers to the contrast between two very different things or ideas is antithesis. Antithesis is often used in literature and rhetoric to highlight opposing concepts, creating a clear distinction that can emphasize differences, enhance themes, or express conflict. By juxtaposing contrasting ideas, writers can create tension or provoke thought, making the antithesis a powerful tool in effective communication.

By contrast, a metaphor involves comparing two unlike things without using "like" or "as," aiming to create a symbolic meaning rather than highlighting their differences. Conceit refers to an extended metaphor or an imaginative comparison that can be elaborate and far-fetched. Irony denotes a discrepancy between what is expected and what actually occurs, often with a humorous or poignant effect, which does not inherently focus on contrasting ideas in the way antithesis does. Thus, antithesis specifically captures the essence of contrasting two distinct elements, making it the most accurate term for the question posed.