Encapsulation is the concept of bundling data (variables) and methods (functions) that operate on the data into a single unit called a class. This is a key principle of object-oriented programming (OOP) and helps to hide the internal details of an object from the outside world. Encapsulation promotes the idea of “data hiding,” which means restricting access to certain components of an object and only exposing those parts that are necessary for interaction.

Definition: Encapsulation is the concept of bundling data and methods that operate on that data into a single unit, or class, and restricting direct access to some of the object’s components.

In practical terms, encapsulation is achieved by using access modifiers like private, protected, and public to control access to an object’s properties and methods. For example, an object’s internal data might be declared as private to prevent direct modification from outside the class. Instead, public methods, known as getters and setters, are provided to access or modify the data in a controlled manner.

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance  # Private variable
    
    def deposit(self, amount):
        self.__balance += amount
    
    def get_balance(self):
        return self.__balance

Encapsulation ensures that objects maintain control over their own state and prevents other parts of the program from inadvertently changing the internal data in ways that could lead to errors. This leads to more robust and maintainable code and helps in enforcing object integrity throughout a program.