What is C#?

C# (pronounced "C sharp") is a modern, general-purpose programming language created by Microsoft. It was designed to build all kinds of software — from desktop apps and websites to video games and cloud services. C# is "object-oriented". This means: you build your program out of small, reusable building blocks called "objects" — for example, an object could be a "player" or a "bank account", each with its own properties (e.g. health, balance) and abilities (e.g. jump, withdraw money).

using System;

class Program
{
    static void Main()
    {
        Console.WriteLine("Hello, C#!");
    }
}

What does this program print when you run it?

using System;

class Program
{
    static void Main()
    {
        Console.WriteLine("Hello, C#!");
    }
}

C# is a programming language that is ____, meaning it works with objects.

C# is also "strongly typed". This means every piece of data has a specific, known kind — such as a whole number or a piece of text — and the language checks that you use it correctly before your program ever runs. This helps catch many mistakes early, instead of letting them cause surprises later.

C# does not work by itself — it is built to run on ".NET" (pronounced "dot net"), a free platform from Microsoft that provides the tools and libraries a C# program needs to actually execute. You will learn much more about how this works later in this level.

C# was created by Google.