Why use the global keyword in C#?

The keyword global:: causes the compiler to bind names starting in the global namespace as opposed to in the current context. It’s needed in places where a bindable member exists in a given context that has the same name as a global one and the global one is desired.

For example

class Test {
  class System {}
  public void Example() {
    System.Console.WriteLine("here"); // Error since System binds to Test.System
    global::System.Console.WriteLine("here"); // Works
}

The corresponding MSDN page has a few more examples (including the one above)

• http://msdn.microsoft.com/en-us/library/c3ay4x3d.aspx