Explanation/Reference:
Explanation:
The following list provides the main features of a static class:
Contains only static members.

Cannot be instantiated.

Is sealed.

Cannot contain Instance Constructors.

Creating a static class is therefore basically the same as creating a class that contains only static members and a private constructor. A private constructor prevents the class from being instantiated.
Reference: Static Classes and Static Class Members (C# Programming Guide)
https://msdn.microsoft.com/en-us/library/79b3xss3.aspx