please introduce a number of OOP features (e.g. encapsulation) and principles (e.g. single responsibility principle).

Sure, here are some common OOP features and principles:

Features:
1. Encapsulation: Encapsulation is the process of hiding the implementation details of an object from the outside world, and restricting access to the object's internal data and methods.
2. Abstraction: Abstraction is the process of creating a simplified version of something complex, in order to make it more manageable and easier to understand.
3. Inheritance: Inheritance is the mechanism by which one class inherits properties and methods from another class.
4. Polymorphism: Polymorphism is the ability of an object to take on many different forms, depending on the context in which it is used.

Principles:
1. Single Responsibility Principle: The Single Responsibility Principle (SRP) states that a class should have only one reason to change. This means that a class should only be responsible for one thing, and should not be responsible for multiple unrelated tasks.
2. Open/Closed Principle: The Open/Closed Principle (OCP) states that a class should be open for extension but closed for modification. This means that you should be able to add new functionality to a class without modifying its existing code.
3. Liskov Substitution Principle: The Liskov Substitution Principle (LSP) states that a subclass should be able to be substituted for its parent class without affecting the correctness of the program. This means that a subclass should be able to use all the methods and properties of its parent class without any issues.
4. Interface Segregation Principle: The Interface Segregation Principle (ISP) states that a class should not be forced to implement interfaces it does not use. This means that you should only include the methods and properties that are necessary for a class to perform its specific tasks in its interface.
5. Dependency Inversion Principle: The Dependency Inversion Principle (DIP) states that high-level modules should not depend on low-level modules, but both should depend on abstractions. This means that you should use interfaces or abstract classes to decouple the high-level and low-level classes, making your code more flexible and easy to maintain.