This declaration
corresponds to the center environment. This
declaration can be used inside an environment such as quote or in a
parbox. The text of a figure or table can be centered on the page by
putting a \centering
command at the beginning of the figure or table
environment.
Unlike the center environment,
the \centering
command does not start
a new paragraph; it simply changes how LaTeX formats paragraph units.
To affect a paragraph unit's format, the scope of the declaration
must contain the blank line or \end
command (of an environment like
quote) that ends the paragraph unit.
\protect
when putting
a \centering
command in a
sectioning command.
For example,
\section{\protect \centering Centered section heading}