C# is a general purpose programming language created by Microsoft. It’s object-oriented (with a few additions of functional language features), and flexible thanks to support for more than one fundamental style of programming.
It is the primary (but not only) language to be used with the .NET framework, and it cannot be used in any other framework.
It is used to build .NET applications like Windows services, web applications, web services, Windows desktop applications, games based on Unity, console applications, REST APIs, and mobile apps for iOS, Android and Windows phone.
This programming language is type-safe, versatile and elegant, it combines the functionality of C with Visual Basic, it’s safer than C++, and it can be used to build robust applications. It is statically typed, which makes it particularly useful for large project teams, giving it a big advantage over dynamically typed languages, for instance Ruby.
It is used in various companies, from small startups to huge enterprises. There are many libraries, reusable components, toolsets and frameworks which reduce development time, and it’s easily scalable. However, it definitely isn’t the fastest language for deploying apps within a short time to market.
For a long time C# wasn’t an open-source technology, but in 2014 Microsoft released the .NET framework and Visual Studio development environment to the public, which made C# much more usable.
Microsoft’s support, being one of the world’s largest technology companies, means that improvements and updates happen more often than it is the case with competing programming languages.
C# is one of the most popular languages, with a huge community of developers using it.