Java import class System

I have a question on class imports, It seems you can call a method with a reduced line if you have imported the class. I don't understand what is the name of this operation, and how is it possible...

For instance :

Why this code

public class test 
{
        public static void main  (String args[])
        {
                System.out.print("Test");
        }
}

Can be replaced by

import static java.lang.System.out;

public class test 
{
        public static void main  (String args[])
        {
                out.print("Test");
        }
}

What happens if you have also an object named "out" ?

Thanks in advance