Why and what is Static used for in Java

Generally speaking, the "static" keyword means that the method or variable marked with the "static" keyword belongs to that class, and you don't need an instance of that class to call upon that specific method or value.

Here's a few examples: First I'm going to show what is needed to call a non-static method from within a static context:

public class Test {
    public static void main(String[] args) {
        Test t = new Test(); //I have to create a static Test instance variable
        t.doStuff(); //then I call the non-static doStuff() method off of that static Test instance variable
    }

    public void doStuff() { //notice that the doStuff() method is not static
        System.out.println("test");
    }
}

The compiler would've spat out an error at me if I didn't add the "Test t = new Test()" and called the doStuff() method off of that Test instance variable.

Now if the doStuff() method is declared as "static" this is all this is needed to run it within Main():

public class Test {
    public static void main(String[] args) {
        doStuff(); //no Test instance variable is needed to call the now static doStuff() method
    }

    public static void doStuff() { //notice that the doStuff() method is static 
        System.out.println("test");
    }
}

I hope this helps, let me know if you're still confused and I can try to re-explain a different way.