Parallel structure involves using the same grammatical pattern for elements that have equal importance. It originated in oral traditions and is used in poetry, rhetoric, and business writing to organize ideas, communicate effectively, and persuade. Parallel structure can be created using words, phrases, or clauses connected with coordinating conjunctions. Examples of parallel structure include verb phrases like "I came, I saw, I conquered" and adjective lists like "Mad, bad, and dangerous to know." Practicing parallel structure involves analyzing examples from everyday speech, advertising, music, and literature and then incorporating it into one's own writing.