Providing access to an object only through its messages, while keeping the details private is called information hiding. An equivalent buzzword is encapsulation. Because experience has taught us that software changes. And some of the costliest mistakes in computer history have come from software that breaks when someone tries to change it. An object is defined via its class , which determines everything about an object.
Objects are individual instances of a class.
For example, you may create an object call Spot from class Dog. Spot You can make more than one object of this class, and call them Spot, Fido, Rover, etc. You may also hear the term method used. A method is simply the action that a message carries out. It is the code, which gets executed when the message is sent to a particular object.