Java is a programming language designed by James Gosling and the Sun Microsystems. It was developed by the Oracle Corp. Java is used for programs and games, and, unlike JavaScript, it is not used on or for the internet. It is very complicated and I advise using Ruby, at least for now. Here is the usual Hello World! program:

class HelloWorldApp {
 public static void main(String[] args) {
 System.out.println("Hello World!");
Which of course give Hello World!. but to do the same program in ruby:
puts "Hello World!"
But Java is much more advanced