The lead section of a Wikipedia article is the section before the first heading. The table of contents, if displayed, generally appears between the lead section and the first subheading.
Rule of thumb: If a topic deserves a heading or subheading, then it deserves short mention in the lead.
The lead section should contain up to four paragraphs, depending on the length of the article, and should provide a preview of the main points the article will make, summarizing the primary reasons the subject matter is interesting or notable. The lead should be capable of standing alone as a concise overview of the article, should be written in a clear and accessible style, should be carefully sourced like the rest of the text, and should encourage the reader to want to read more. The following table has some general guidelines for the length of the lead section: