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 ...
...
In addition to providing the heading in the text, the mandatory
argument of the sectioning command can appear in two other places:
The title or optional title are moving arguments so fragile commands contained in these arguments must be protected.
All the sectioning commands have *-forms that print a title, but do not print a number with the title and do not incement the relevant counter and do not make an entry in the table of contents.
A blank line before or after a sectioning command has no effect.