Class

In a nutshell, classes are essentially user defined data types. Classes are where the programmer creates a blueprint where they define some attributes and behaviors. Individual objects are instantiated, or created from this blueprint.

For Example: -

we define Animal as class. This Animal class have name, age and food as an attribute and eat as behavior (Method)

Object

Objects are instances of classes created with specific data, for example cat is an instance of the animal class and it contain value for each attribute.

Attribute

Attributes are the information that is stored. Attributes are defined in the Class template. When objects are instantiated, individual objects contain data stored in the Attributes field.

For Example, cat object has value store in name, age and food field.

Method

Methods represent behaviors. Methods perform actions; methods might return information about an object, or update an object’s data.

For Example, the animal class have a method eat that display the food information eaten by a particular animal object.

Note: -

Operation is an action or transformation that an object performs. A specific implementation of operation by a certain class is called method.

Encapsulation

Encapsulation is containing all important information inside an object, and only exposing selected information to the outside world. Then, when an object is instantiated from the class, the data and methods are encapsulated in that object.

Encapsulation allows us to protect the data stored in a class from system-wide access. We can implement encapsulation keeping the fields (class variables) private and providing public.

By making fields private no one can see what’s behind the object’s curtain.

Abstraction

Abstraction hides the implementation details while just presenting the feature to the outside world.

For example, you don’t have to know all the details of how the engine works to drive a car. The engineering is hidden from the driver.

In terms of OOP when we use any object and call method then we don't need to bother about internal implementation of that method. So, in above mention example when we have animal object(cat) then we simply call eat () method without knowing the implementation of eat method.

Polymorphism

Polymorphism allows the same method to execute different behaviors.

Inheritance Inheritance allows classes to inherit features of other classes. Put another way, parent classes extend attributes and behaviors to child classes. Inheritance supports reusability – if basic attributes and behaviors are defined in a parent class, child classes can be created extending the functionality of the parent class, and adding additional attributes and behaviors.

For Example, we have a Dog class. French Bulldogs are a special type of dog that requires more attention than your average dog. We can create a child class French Bulldog from the parent class Dog, and then add behaviors.