[Java] When to use "static"?

Question

How come I can write "static" here:

public class Main {
final static String MY_CONST = "hello";
public static void main(String[] args) {

}
}

but not here:
public class Main {
public static void main(String[] args) {
final String MY_CONST = "hello";

}
}

Why can't I use static within my main method like this:

public class Main {
public static void main(String[] args) {
final static String MY_CONST = "hello";

}
}

Answer 1

The static keyword is used to make a variable/method belong to a class, so that you can use the variable/method without creating an object of the class. This is called static access.
It doesn't make sense to declare a static variable inside a method. Variables you declare inside a method are only accessible inside the method (they are local variables), so they cannot belong to the class, only to the method inside the class.

Answer 2

static keyword is used when value of a particular class or its corresponding variable has to be made fixed throught the execution of a particular function.