Difference Between Break and Linebreak Commands

Question

The motivation for this question originates from the answer given to Centering an Arabic Section Number Above Justified Title Text

Consider the code

\documentclass{book}
\usepackage{titlesec}
\titleformat{\section}[display]
  {\sffamily\Large\bfseries}
  {\filcenter\thesection}
  {1.25ex}
  {\justifycenter}
\newcommand{\justifycenter}[1]{%
  \leftskip=0pt plus 1fil
  \rightskip=0pt plus -1fil
  \parfillskip=0pt plus 2fil
  #1%
}
\renewcommand{\thesection}{\arabic{section}.}
\begin{document}
\large
\thispagestyle{empty}
\section{Section Title on Which I Would Like to Employ the Linebreak Command; When I Do, Although the\break Output is Correct, I Receive an Error Message.\break However, No Such Error Message Results When I Use the Break Command.}
\end{document}

which produces the desired output

In the code, I make use of the \break command in order produce a break in the line without losing the desired justification. I normally would use \linebreak, but for some reason unbenownst to me, it produced the desired result---though always with a series of error messages. Again, strangely, the command seemed to work, but not without a display of error messages.

After searching this site for an alternative to the \linebreak command, I came across the \break command---and it seems to work fine---no error messages.

QUESTION: In ordinary circumstances, is there any reason to prefer \break over \linebreak (or visa-versa)? Do they both do the same thing? After reading some comments pertaining to the use of \linebreak, it gave me the impression that one should use \linebreak it as little as possible, though I don't recall any specific reasons being given. What kinds of ``badness'' can be expected with the use of \linebreak? Do the same apply to \break?

Thank you.