C# or C-Sharp is the programming language behind .NET (dotnet) and the Unity framework. It was created at Microsoft as a C-like object-oriented language and is used to build apps for web, desktop, ...

C# (pronounced see sharp) is a multi-paradigm programming language encompassing strong typing, imperative, declarative, functional, generic, object-oriented, and component-oriented programming ...

There are many programming languages to learn. For SEO, the programming language you choose depends on what you plan to do with that language and how you plan to implement changes from that language.