An antithesis (plural: '"antitheses'") is a figure of speech which contrasts two opposite ideas with similar sentence structures in one statement. This word is derived from the Greek anti, which means opposite, and thesis, which means setting.
Antithesis is often used to express contrasting ideas and strengthen arguments by pointing out differences. This makes it more memorable and catchy for readers and listeners alike in literature, advertisements and music. It does the latter by showing that the arguer's own idea is better.
When used correctly, it can make writing tense and dramatic, allowing readers to explore complex themes and ideas.