The L^AT_EX typesetting system is similar to other markup languages as XML, used for many types of documents (including the one you are reading), or HTML, used for web pages. The general idea is about having specially wrapped keywords, called tags, that tell a program (a word processor, a web browser, or the Kile compiler) how to present text. Kile offers you a good number of such tags in the menu LaTeX in the menu bar.

While we will try to give you a good idea of what L^AT_EX is, this is not The Definitive Book on L^AT_EX. If you want to learn L^AT_EX well, you may want to loan a book in your library. The writer has had a good experience with A Guide to L^AT_EX by H. Kopka and.P. W. Daly, and still keeps it on the shelf.

As other markup languages, L^AT_EX contains a preamble, which sets global commands, such as paper size, page numbering, dimensions of the text on the page, and a body, that contains the document text; the preamble contains at least the \documentclass command, and precedes the body, that starts with the command \begin{document}, and is quite predictably concluded by the command \end{document}.