Sectioning commands provide the means to structure your text into units. The document style determines which sectioning commands are supported. They should be used with the following heirarchy:
The counter for each level is reset when the level above is incremented (except chapters are numbered sequentially regardless of the part).
All sectioning commands take the same general form:
\chapter[optional]{title} \label{lab} % optional, for cross referencing text for this unit ... ...A blank line before or after a sectioning command has no effect.
In addition to providing the heading in the text, the mandatory argument of the sectioning command can appear in two other places:
The sectioning commands have *-forms that print a title, but do not include a number and do not make an entry in the table of contents. For example, the *-form of the \subsection command could look like:
\subsection*{Example subsection}