A paragraph is a group of sentences that together discuss one main idea or topic. It is part of a larger composition and functions as a miniature essay. A good paragraph has unity around a single topic, supporting details that provide evidence for the main idea, and coherence through logical organization and connection of ideas. There are different types of paragraphs including descriptive, narrative, expository, persuasive, compare and contrast, and cause and effect paragraphs. Effective paragraph writing involves planning, drafting, and revising to craft a clear introduction, body, and conclusion.