The cookie cutter
A cookie cutter is a template; each cookie stamped from it is a separate treat with its own sprinkles. In Java a class is the cutter and an object is a cookie — one blueprint, many individual things made from it.
Classes are blueprints
A class defines fields (data) and methods (behavior). An object is an instance created from that class with the new keyword.
class Dog {
String name;
void bark() { System.out.println("Woof"); }
}
Dog d = new Dog(); // an object