C# What is C# and .NET?

Lesson notes

What is C# and .NET?

Learn that C# is a powerful, modern language and how the .NET runtime works.

What is C#?

C# is a powerful, type-safe programming language developed by Microsoft. With version 12 it is a modern, multi-purpose language.

C# programs run on the .NET platform. .NET provides an environment that compiles and runs your code.

You can build websites, desktop apps, games (Unity) and cloud services with C#.

What can you build with C#?

C# is a multi-purpose language. The most common use cases are:

Web: fast and secure sites with ASP.NET Core
Desktop: window apps with Windows Forms or WPF
Games: 2D and 3D games with the Unity engine
Cloud: microservices on Azure

This flexibility makes C# popular worldwide.

Test yourself

Where do C# programs run?
- On the Java virtual machine
- On the .NET platform
- In the browser
- In the operating system kernel
Show answer

On the .NET platform — Correct! C# code runs on the .NET platform.
Match the concepts

C#

Language
.NET

Platform
CLR

Runtime
IL

Intermediate code
Which can NOT be done with C#?
- Build a website
- Make a game (Unity)
- Write a browser extension
- Build a desktop app
Show answer

Write a browser extension — Correct! Browser extensions are written in JavaScript, not C#.

Where does C# run?

C# runs on the ____ platform.

Show answer

C# runs on the .NET platform.

Next lesson: Your first program