HelloPlanet                                                   P.Komisar
 

class HelloPlanet{                 // Everything in java is defined inside a class. Here the class is called HelloPlanet
   public static void main(String[] args){                // The main method is the starting point of  a Java program.
   System.out.println("Hello World in Java " );         // This is how you get character strings out to the console
  }                       // Each pair of curly braces define a  scope or range of related code. Here the main method ends
}                                                                                                                            // Here the class ends
 

Steps

1) The source code needs to be saved as a simple text file, with the same name as the class and appended
    with the .java extension.(i.e HelloPlanet.java)  Note Java is case sensitive so helloplanet is considered a
    different name

2)  The source file's name with extension is provided as an argument to the java compiler, javac. In other
      words, type javac HelloPlanet.java at the command line of the system you are using.

3)  Once compiled without errors, a class file is produced, (a file by the same name as the source file
     with a .class extension) This contains the architecturally neutral bytecode.

4) The name of the class file (without the .class extension) is supplied as an argument to java ,the java
     interpreter, also known as the JVM. The JVM translates the architecturally neutral bytecode of the
    class file into the executable format of the native machine.