As already noted, commands begin with a backslash character,
`\'. Command arguments are enclosed in curly braces, and these
are sometimes used to delimit the scope of more local options such
as font changes.
The scope of an environment is normally delimited by using the form:
\begin{..environmentform..} .... \end{..environmentform..}and we have already seen an example of the use of this form with the \begin{document} and \end{document} commands. Other environments include itemize for bulleted lists, enumerate for numbered lists, quote for indented quotation blocks and so on. In general these forms can be nested without any problems.
More local options such as font changes can be denoted by a short form as in {\bf ...} to embolden the enclosed character string, and {\em ...} to italicise it.