The document discusses the key elements of a well-written paragraph: a topic sentence that states the main idea, supporting sentences that provide details and evidence to expand on the topic sentence, and a concluding sentence that restates the main point. It also outlines the four essential elements of a cohesive paragraph: unity, where all ideas are connected to the topic; order, how the ideas are logically organized; completeness, where all aspects of the topic are addressed; and coherence, how smoothly the reader can understand it.