C# started as Microsoft’s answer to Java in 2000. Since then, it has grown into one of the most productive languages for building real software.

It powers Unity games, Windows desktop apps, enterprise backends, cloud services, and a growing amount of cross-platform server code through .NET.

This course takes you from your first line of C# to the features experienced .NET engineers use every day.

You don’t need any prior C# experience. You also don’t need to install the .NET SDK. Everything is set up so you can start writing and running code right away.

The lessons are short and focused. Each one explains a single idea, gives you runnable code, and ends with exercises that help you apply what you just learned.

The fundamentals are best followed in order. After that, the course becomes more modular, so you can jump into the topics you care about most.

The course is divided into four broad parts. Each part builds on the previous one, so you can move from the basics to real-world C# step by step.

The early sections build your foundation. The later sections are where C# starts to feel really powerful and enjoyable to write.

LINQ makes working with collections feel clean and expressive, almost like querying data with SQL. async and await make asynchronous code much easier to read and reason about.

But both of these features make a lot more sense once you understand the basics underneath them, so the course is structured to help you build up to them naturally.

Most C# tutorials use examples that feel disconnected from real software: an Animal class with Dog and Cat, a Shape class, or a simple grade calculator.

This course takes a more practical approach.

Every example is built around a small online store: products, stock counts, shopping carts, orders, customers, reviews, and delivery statuses like placed, shipped, and delivered.

The benefit is that the examples keep building on each other. The Product class you create in the OOP section comes back later when you query products with LINQ, serialize them to JSON, and save them to a database.

You don’t have to learn a new example in every lesson. You keep working with a familiar domain while the C# concepts become more powerful.

You don’t need any e-commerce background. If you have ever ordered something online, the vocabulary will feel familiar. No SKUs, no payment processors, no jargon.

This course is genuinely interactive.

Most C# code blocks on the site has a Run button. Click it, and your code compiles and runs directly in the browser, with the output shown right below.

You can edit the code, change values, add a line, break it on purpose, and run it again to see what happens.

The .NET base class library is available too, so types from System, System.Collections.Generic, System.Linq, System.Text, System.IO, and more work without any extra setup.

You don’t need to install anything to get started. No .NET SDK. No Visual Studio. No dotnet new.

Later, if you want to set up C# on your own machine, lesson 5 of the introduction section walks you through it. Every example in this course can be copied and run locally without changes.

A few practical things about the runner:

Run this before you start. If you see the expected output, your browser is set up correctly and the rest of the course will work the same way.

If that worked, you're set. If you got an error or nothing happened, refresh the page. If it still won't run, let us know in the comments or through the feedback button.