A paragraph is a set of related sentences that explain or prove one idea. The idea
that is explained or proved in the paragraph is called the main idea. If the main idea is a sentence that occurs in the paragraph, that sentence is called the topic sentence. The related sentences, called support sentences, are of two kinds: major support sentences and minor support sentences. Major support sentences directly explain or prove the idea of the paragraph. Minor support sentences further explain or give more information about the major support sentences.