Question

Give a real life example that the abstraction is applied. i.e. we use things without known the internal structure of the thing.

Answer 1

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 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.

Consider the Application of Library Management System in a college. Around thousands of books lies in library and each and every books is stored and maintained in there database . Also the authority brings new books every year and may remove the older books.

The internal implementation (logic) of accessing information i.e connecting to db,make a query ,fetch result in resultset etc .is kept hidden to end user (librarian here ). This is abstraction.

If you observe almost everything/object(TV,FAN,Freeze,washing machine….) shows the nature of encapsulation and abstraction, you can interact with the thing through certain mechanism(functionality) and sometimes you gets surprised by thinking how it works.

Abstraction is Just Hiding the complex things behind a particular Procedure to make the procedure look simple.
Example:Monitor ON/OFF::--The user doesn't need to know much about all the chips functioning that happens when Monitor is switched ON or OFF..All he needs to know is On Function ON-Monitor is On and on function OFF-Monitor is off...

Or Better Look for a car--Everyone Knows that There's a special Gear machine Which changes the gear,nobody bother to know what all functionality undergoes for a gear to change..So,That's abstraction(avoiding unwanted implementations to prevent Complexity).