\begin{verbatim}
text
\end{verbatim}
or
\begin{verbatim*}
text
\end{verbatim*}
The verbatim environment is a paragraph-making environment that gets LaTeX to print exactly what you type in. It turns LaTeX into a typewriter with carriage returns and blanks having the same effect that they would on a typewriter. The output looks exactly as it looks in the input file.
The difference between verbatim and verbatim* is that the latter prints spaces as "visual" spaces, i.e., a short, squat "u".
The only text which cannot be placed in the verbatim environment is the 14-character sequence "\end{verbatim}".
The verbatim environment may not be used in the argument of another command. However, it can be placed inside a minipage environment which allows you to manipulate it's placement.
Also see \verb