Static classes in C#

Static Classes:

•     A  class can be declared static, indicating that it contains only static members.

•     It is not possible to create instances of a static class using the new keyword. 

•    Static classes are loaded automatically by the  .NET Framework common language runtime

•   (CLR).

The main features of a static class are:

• They only contain static members.
• They cannot be instantiated.
• They are sealed. 
• They cannot contain Instance Constructors
• Creating a static class is therefore much the same as creating a class that contains only static members and a private constructor. A private constructor prevents the class from being instantiated.
• The advantage of using a static class is that the compiler can check to make sure that no instance members are accidentally added. The compiler will guarantee that instances of this class cannot be created.
• Static classes are sealed and therefore cannot be inherited. Static classes cannot contain a constructor, although it is still possible to declare a static constructor to assign initial values or set up some static state.