Object-Oriented Programming (OOP) is based on four important principles:

1. Encapsulation

• Definition: Encapsulation is the concept of bundling data (attributes) and the methods (functions) that operate on the data into a single unit (a class).
• Purpose: It helps in hiding the internal details of how an object works, providing a clear interface for interacting with the object for the users of that object.

2. Inheritance

• Definition: Inheritance allows a new class (subclass or derived class) to inherit the characteristics and behaviors of an existing class (superclass or base class).
• Purpose: It promotes code reusability and establishes a relationship between classes, making it easier to manage and extend code.

3. Polymorphism

• Definition: Polymorphism means the ability of a single function or method to work in different ways based on the context or the types of objects it is operating on.
• Purpose: It enhances flexibility and enables code to be more generic, allowing the same function or method to be used with different types of objects.

4. Abstraction

• Definition: Abstraction involves simplifying complex systems by modeling classes based on the essential properties and behaviors, while ignoring unnecessary details.
• Purpose: It helps in managing complexity by focusing on what an object does without needing to understand the internal implementation details. Abstraction allows developers to work at a higher level of abstraction.

These four principles promote the following coding practices:

• Modularity: Breaking down a program into smaller, self-contained parts making it easier to understand, develop, and maintain.
• Reusability: Creating classes and components that can be easily used in different parts of a program or in other programs, reducing the need to rewrite code and promoting efficiency in software development.
• Maintainability: Designing code in a way that allows for easy updates, bug fixes, and enhancements, ensuring that the software remains manageable and adaptable over time without causing unintended side effects.

We will learn about each principle in detail in the following chapters.