What is the purpose of the static keyword in C#?

In C#, the static keyword serves several purposes:

1. Static members: Using the keyword “static” allows for the definition of static members, including static fields, static methods, and static properties. Static members belong to the class rather than the instance, so they can be accessed directly by the class name without creating an instance of the class.
2. Static class: Using the static keyword, a static class can be defined. A static class can only contain static members, cannot be instantiated, and cannot be inherited.
3. Singleton pattern: By declaring the class constructor as private and using static members to provide access to the unique instance, the singleton pattern can be achieved.
4. Namespace: using the static keyword allows for defining a static namespace, where all members can be accessed directly without requiring a namespace prefix.

In general, the static keyword is used to define static members and static classes, allowing for a unified way to access class members without having to create an instance of the class.