Java is an object-oriented programming language, that appeared in 1995. The 
most recent version of the programming language is version 16\footnote{March 
2021}. In order to write Java programs, one needs to install the so-called 
\emph{Java Development Kit 
(JDK)}.\footnote{\url{https://www.oracle.com/java/technologies/javase-downloads.html}}
 Java programs can be written independently from the operating system that one 
uses.