OOPS Full Form: Object Oriented Programming System

OOPS stands for Object Oriented Programming System.

The shorter form OOP stands for Object Oriented Programming. Both names describe the same style of writing software. You will see OOP in textbooks and OOPS in course syllabi and interview lists.

The S is the only difference, and it adds nothing to the meaning. Treat OOPS and OOP as the same term.

Short form	Full form
OOP	Object Oriented Programming
OOPS	Object Oriented Programming System
OOPs concepts	The main ideas of object oriented programming
OOA	Object Oriented Analysis
OOD	Object Oriented Design

What object oriented programming means

Object oriented programming is a way of organising code around objects instead of around steps.

An object is a piece of data plus the functions that work on that data. A class is the template that describes what an object holds and what it can do.

A simple example helps. A BankAccount class holds a balance and defines deposit and withdraw. Each account you create is one object of that class.

The alternative is procedural programming, where data and functions live apart. Object oriented code keeps them together, which makes large programs easier to change.

The four main concepts of OOPS

Interview lists almost always ask for these four. Learn one clear sentence and one example for each.

Concept	What it means	Example
Encapsulation	Keep data and its methods in one class, and hide the data	A private balance field with public deposit and withdraw
Inheritance	A new class reuses the fields and methods of an existing one	`Dog` and `Cat` both extend `Animal`
Polymorphism	One call runs different code depending on the real object	`speak()` on an `Animal` reference barks or meows
Abstraction	Show what an object does and hide how it does it	A `Shape` with a `draw()` method that each shape defines

Some lists add a fifth item, such as classes and objects, or message passing. The four above are the set most interviewers expect.

Class and object, in plain terms

These two words cause more confusion than the four concepts do.

A class is a blueprint. It exists in your source code and describes structure and behaviour.
An object is one built item. It exists in memory while the program runs and holds real values.
One class makes many objects. A single User class can produce a million user objects.
A method is a function inside a class. It works on the data of the object it is called on.

Which languages are object oriented

Most languages you meet at work support this style.

Java, C#, Python, C++, Ruby, Kotlin, Swift and PHP all have classes and objects. JavaScript does it with prototypes and a class syntax on top. Go and Rust have no inheritance, but they get similar results with interfaces and traits.

C is not object oriented. You can copy the idea with structs and function pointers, but the language gives you no help.

Why teams use it

Object oriented code is not automatically better. It pays for itself in large, long lived systems.

Reuse. Inheritance and composition let you build on what already works.
Change safety. Private data means one class can change without breaking callers.
Shared vocabulary. Class names match real things, so new team members read the code faster.
Testing. Small classes with clear inputs are easier to test in isolation.

How to Prepare

Give the full form and one example. "Object Oriented Programming System" followed by a class and object example is a complete answer.
Practice all four concepts out loud. Most interviews ask you to define them, then show one in code.
Write a small class design. A parking lot or a library system is the usual warm up question.
Connect objects to design work. Class boundaries are the first step of system design. Grokking the System Design Interview shows how those boundaries scale up.
Keep coding practice going alongside. Grokking the Coding Interview covers the algorithm rounds that sit next to the theory round.
Learn the other short forms too. Interviewers mix them freely. See the full form of API, SDK, IDE and REST.