\centeringSynopsis:
{\centering ... }
or
\begin{group}
\centering ...
\end{group}
Center the material in its scope. It is most often used inside an
environment such as figure, or in a parbox.
This example’s \centering declaration causes the graphic to be
horizontally centered.
\begin{figure}
\centering
\includegraphics[width=0.6\textwidth]{ctan_lion.png}
\caption{CTAN Lion} \label{fig:CTANLion}
\end{figure}
The scope of this \centering ends with the \end{figure}.
Unlike the center environment, the \centering command does
not add vertical space above and below the text. That’s its advantage
in the above example; there is not an excess of space.
It also does not start a new paragraph; it simply changes how LaTeX
formats paragraph units. If ww {\centering xx \\ yy} zz is
surrounded by blank lines then LaTeX will create a paragraph whose
first line ‘ww xx’ is centered and whose second line, not centered,
contains ‘yy zz’. Usually what is desired is for the scope of the
declaration to contain a blank line or the \end command of an
environment such as figure or table that ends the
paragraph unit. Thus, if {\centering xx \\ yy\par} zz is
surrounded by blank lines then it makes a new paragraph with two
centered lines ‘xx’ and ‘yy’, followed by a new paragraph with
‘zz’ that is formatted as usual.