Latex is a markup language for typesetting documents, built on top of the TeX typesetting system. It allows for high quality typesetting, easy inclusion of math formulas, and is platform independent. Latex uses markup tags to denote headings, lists, tables, images, and bibliographies. It separates content and formatting, making documents easy to update. Common document classes include article, report, and book. Packages add functionality. The document structure includes the preamble, body, and bibliography.