15.2 \indent & \noindent

Synopsis:

\indent

or

\noindent

Go into horizontal mode (see Modes). The \indent command first outputs an empty box whose width is \parindent. These commands are robust (see \protect).

Ordinarily you create a new paragraph by putting in a blank line. See \par, for the difference between this command and \par. To start a paragraph without an indent, or to continue an interrupted paragraph, use \noindent.

In the middle of a paragraph the \noindent command has no effect, because LaTeX is already in horizontal mode there. The \indent command’s only effect is to output a space.

This example starts a fresh paragraph.

... end of the prior paragraph.

\noindent This paragraph is not indented.

and this continues an interrupted paragraph.

The data 

\begin{center}
  \begin{tabular}{rl} ... \end{tabular}
\end{center}

\noindent shows this clearly.

To omit indentation in the entire document put \setlength{\parindent}{0pt} in the preamble. If you do that, you may want to also set the length of spaces between paragraphs, \parskip (see \parindent & \parskip).

Default LaTeX styles have the first paragraph after a section that is not indented, as is traditional typesetting in English. To change that, look on CTAN for the package indentfirst.