As stated in the first edition of C# Language Specification (EMCA-334):
C# is intended to be a simple, modern, general-purpose, object-oriented programming language.
C# is intended to be suitable for writing applications for both hosted and embedded systems, ranging from the very large that use sophisticated operating systems, down to the very small having dedicated functions.
Thus it is apparent that C# is designed to be used in literally any application domain (if performance consideration is not taken into account).
Albeit its versatility, C# has mainly been used for developing commercial applications including:
- business applications
- web applications
In fact, almost the entire .NET framework is written in C# (jasonall, 2008)
References
- International, E. (2001). C# Language Specification (1st ed.). Retrieved from https://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-334%201st%20edition%20December%202001.pdf
- jasonall. (2008, May 25). A Brief History Of C# Style. Retrieved from https://blogs.msdn.microsoft.com/sourceanalysis/2008/05/25/a-brief-history-of-c-style/