Encapsulation VS Abstraction in Object-Oriented Programming

Encapsulation binds together the data and functions that manipulate the data, keeping it safe from interference and misuse.

Real-World Example: Every time you log into your email account( Gmail, Yahoo, Hotmail or official mail), you have a whole lot of processes taking place in the backend, that you have no control over. So your password, would probably be retrieved in an encrypted form, verified and only then you are given access. You do not have any control, over how the password is verified, and this keeps it safe from misuse.

Abstraction is a process of hiding the implementation from the user, only the functionality is exposed here. So you are aware only of what the application does, not how it does it.

Real-World Example: When you log into your email, compose and send a mail. Again there is a whole lot of background processing involved, verifying the recipient, sending a request to the email server, sending your email. Here you are only interested in composing and clicking on the send button. What really happens when you click on the send button, is hidden from you.

Let's take another real life example:
Suppose you go to an automatic cola vending machine and request for a cola. The machine processes your request and gives the cola.

• Here automatic cola vending machine is a class. It contains both data i.e. Cola can and operations i.e. service mechanism and they are wrapped/integrated under a single unit Cola Vending Machine. This is called Encapsulation.
• You need not know how the machine is working. This is called Abstraction.
• You can interact with cola can only through service mechanism. You cannot access the details about internal data like how much cans it contains, mechanism etc. This is Data Hiding.
• You cannot pick the can directly. Your request for cola through proper instructions and request mechanism (i.e. by paying an amount and filling request) and get that cola only through the specified channel. This is message passing.

The working and data are hidden from you. This is possible because that Vending machine is made (or Encapsulated or integrated) so. Thus, we can say Encapsulation is a way to implement Abstraction.

Reference: Quora.