My Latex code is:
\documentclass{article}
\begin{document}
\author{Author}
\title{Title}
\maketitle
Document's text.
\end{document}
How can I show the author's position underneath the author's name, e.g. Professor at ...?
The standard article class has no further fields. But you can put additional information into the \author command, like
\author{Author\\Some University}
which will result in
\documentclass{article}
\begin{document}
\author{Author\\Some University}
\title{Title}
\maketitle
Document's text.
\end{document}
For more complicated arrangements of multiple authors with mixed affiliations consider to use the package authblk.
articleclass has no further fields. But you can write something like\author{Author\\Some University}. – gernot Dec 11 '16 at 23:00