A static variable is one that’s associated with a class, not objects of that class.Static variable’s value is same for all the object(or instances) of the class or in other words you can say that all instances(objects) of the same class share a single copy of static variables.

Below is the syntax to declare static variable

        static int salary ;

To understand this further lets look at teh e.g. below

class Calculator
{
   static int initialValue=0;
   public void Add()
   {
       initialValue++;
   }
   
   public static void main(String args[])
   {
		//Create 2 new instance of calculatro class 
       Calculator obj1=new Calculator();
       Calculator obj2=new Calculator();
	   
       obj1.Add();
       obj2.Add();
	   
       System.out.println("Obj1: count is=" +  obj1.initialValue);
       System.out.println("Obj2: count is=" +  obj2.initialValue);
   }
}

Output

Obj1: count is=2

Obj2: count is=2

As you can see in the above example that both the objects of class, are sharing a same copy of static variable that’s why they displayed the same value