Sometimes you would like LATEX to output things exactly as you type them,
without interpreting special characters in the input. This would be
particularly useful when including some programming source code in your
document, for example. You can do this with the verbatim
environment. That is, if you put the command \begin{verbatim} at
the beginning of some text and \end{verbatim} at the end,
then LATEX will reproduce the text in the output, in typewriter style, exactly
as it is typed in the input. Spaces and ends-of-line are copied to the output as well as
other special characters.
If you want to include just a few words of verbatim output in the middle
of a paragraph (as I do many times in this paper), you can use \verb.
This command takes a special form: \verb=verbatim text=. The
text between the two equal signs is copied directly to the output in
typewriter style. This text can contain any character except an equal sign,
but cannot extend over more than one line. (If the text you want to output
does contain a =, you can replace the = in the \verb command with any other character.)
One problem with \verb is that it doesn't work inside the parameters
of other commands, such as \footnote.