c# - What is the use of a static class

Question

What is the use of a static class? I mean what are benefits of using static class and how CLR deals with static classes?

Answer 1

A static class simply denotes that you don't expect or need an instance. This is useful for utility logic, where the code is not object-specific. For example, extension methods can only be written in a static class.

Pre C# 2.0, you could just have a regular class with a private constructor; but static makes it formal that you can never have an instance (there is no constructor*, and all members must be static).

(*=see comment chain; you can optionally have a type initializer (static constructor aka .cctor), but you cannot have an instance constructor (aka .ctor)).