Static members

• A static member is a member that exists only once per class, as opposed to once per object.
• When you declare a field to be static, that means that this field exists only once per class, as opposed to once for each object (such as the nextID field of the Body object).
• A static method is invoked on behalf of the entire class.
• A static method can access only static variables and static methods of the class.

      prime = Primes.nextPrime();
      id = Vehicle.currentID();