An object is an instance of a class that encapsulates data and behavior. It represents a real-world entity or concept in the program.
A class is a blueprint or template for creating objects. It defines the properties (attributes) and behaviors (methods) that objects of that class will have.
An instance variable is a variable defined within an object. Each object created from the same class will have its own copy of instance variables.
A method is a block of code that defines the behavior of an object. It can perform actions or manipulate the data within the object.