1. Class

  • A blueprint / template for creating objects.
  • It defines fields (data) and methods (behavior).
  • Does not occupy memory until you create an object.
class Car {
    String color;
    void drive() {
        System.out.println("Driving...");
    }
}

2. Object

  • A runtime entity created from a class.
  • When you do new Car(), Java allocates memory and creates an object.
  • Objects hold actual values in their fields.
Car car1 = new Car();  // object created
car1.color = "Red";

Here,car1is an **object** of classCar`.

3. Instance

  • “Instance” is another word for object, but emphasizes the relationship with its class.
  • You can say:
    • car1 is an object of type Car.
    • car1 is an instance of class Car.

差不多一个意思

👉 The difference is mostly in wording:

  • object → physical entity in memory.
  • instance → conceptual: “this object belongs to that class”.