Java is an object-oriented programming language that appeared in 1995. 
The most recent long-term support version of the programming language is Java SE 21 \footnote{released in September 2023}.
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.
