How not to render section-level headers in bold?

Question

I would like to turn off bold for section-level headers in LaTeX, but keep bold for subsection-level headers. Would this be possible? The document class I'm using is article. Thanks!

A MWE would be:

\documentclass{article}
\begin{document}
\section{This should not appear bold.}
\subsection{This should appear bold.}
\end{document}

EDIT: Would it maybe even be possible to do this only for one section, so:

\documentclass{article}
\begin{document}
\section{This should not appear bold.}
\subsection{This should appear bold.}
\section{This should appear bold again.}
\end{document}

Answer 1

There must be many ways to achieve your formatting objective. A particularly easy way is to exsecute

\usepackage{sectsty}
\sectionfont{\mdseries}

in the preamble.

Observe that these instructions do not change the default relative font sizes -- \Large for section-level headers, \large for subsection-level headers, etc. To change the font size of section-level headers to, say, \large, you'd just have to add \large to the argument of \sectionfont.

\documentclass{article}
\usepackage{sectsty}    % https://www.ctan.org/pkg/sectsty
\sectionfont{\mdseries}
\begin{document}
\section{Hello}
\subsection{World}
\end{document}

---

Addendum to address the OP's follow-up question: To limit the effect of \sectionfont{\mdseries} to just sectioning header, just issue the instruction \sectionfont{\bfseries} before the next \section directive gets executed.