Object-Oriented Programming

Object-Oriented Programming

A clear explanation of OOP without complicated jargon

What is Object-Oriented Programming? (explained without complications)

If you’re just starting out in programming (or you’ve been at it for a while but this never clicked), you’ve probably heard the term Object-Oriented Programming or simply OOP a thousand times.

And it’s also likely that after reading definitions like:

“It’s a paradigm based on classes, objects, inheritance, polymorphism, and encapsulation…”

you ended up just as confused or worse. So let’s talk plainly.

First: why does Object-Oriented Programming exist?

OOP wasn’t born to make our lives harder. It was born because code became large, complex, and difficult to maintain.

At first, programs were small:

  • functions
  • variables
  • one file
  • everything worked

But when systems grew:

  • more rules
  • more people working
  • more changes

the code became a tangled mess.

Object-Oriented Programming tries to solve this with a simple idea:

Model software like real-world things, each with its own responsibility.

So… what is an object?

An object is simply:

  • something that has data
  • and can do things

For example, think of a User.

A user:

  • has a name
  • has an email
  • has a password (hopefully hashed)
  • can register
  • can log in

In OOP, that User becomes an object.

And what is a class?

A class is the blueprint, the mold, the recipe. If the object is the car you drive, the class is the car’s design.

Mental example:

  • Class: User
  • Objects: John, Maria, Peter

They’re all users, but each with different data.

The 4 concepts they always mention (but rarely explain well)

1. Encapsulation

It’s a fancy way of saying:

“Don’t expose what doesn’t need to be exposed.”

An object should protect its internal state and let others interact with it only through what it allows.

This prevents:

  • accidental changes
  • fragile dependencies
  • hard-to-track bugs

2. Abstraction

To abstract is to keep what’s important and hide what’s irrelevant.

When you use a car:

  • you don’t think about the engine
  • you don’t think about combustion
  • you just drive

In code, it’s the same:

  • you use what you need
  • without knowing how it’s implemented inside

3. Inheritance

Inheritance allows a class to reuse behavior from another.

But be careful! Misused inheritance creates more problems than solutions.

Nowadays:

  • it’s used less
  • composition is preferred

But it’s still important to understand it.

4. Polymorphism

It sounds complicated, but the idea is simple:

Different objects can respond differently to the same message.

This allows:

  • more flexible code
  • fewer if/else statements
  • extensible systems

OOP is NOT the solution to everything

And this is important to say from the first blog post:

Object-Oriented Programming:

  • is not perfect
  • doesn’t apply equally to all problems
  • is not always the best option

Nowadays we use:

  • functional programming
  • hybrid approaches
  • event-driven architecture

But understanding OOP remains key, especially in:

  • C#
  • Java
  • enterprise systems
  • modern backend

The most important idea you should take away

If you only remember one thing from this article, let it be this:

OOP isn’t about classes, it’s about responsibilities.

When you think about objects, ask yourself:

  • what does it do?
  • what is it responsible for?
  • what should it NOT do?

If you do that right, the rest falls into place.

Wrapping up…

This blog is the first in a series where I’ll talk about:

  • modern C#
  • real backend
  • architecture without smoke and mirrors
  • common mistakes I see every day

If you’re just starting out or want to level up, stick around.

Let’s go step by step!