Java is a very high-level, object-oriented programming language developed by Sun Microsystems. It is relatively easy to understand if you know C. Like C/C++, it is a compiled language, but it will run on a multitude of platforms. Java programs are compiled into class files that contain what is known as byte-codes, which are not specific to a certain operating system or processor. Java is used for writing both applets, which are mini-programs that run within web browsers, and applications, which are stand-alone. However there is a trade-off to Java's cross-platform functionality: it is quite slow compared to programs written in C.
Java "Hello World" Applet
/*
* The HelloWorldApp class implements an application that
* simply displays "Hello World!" to the standard output.
*/
class HelloWorldApp {
public static void main(String[] args) {
System.out.println("Hello World!"); //Display the string.
}
}