The imports keyword is only used to create a shorthand notation for ease of use of the underlying namespace classes. When converted to MSIL the hardcoded IL written is actually System.Console.WriteLine ...
You are actually "importing" the functionality of an assembly when you add it to your project reference's file. P.S you can only use Imports when an external assembly is referenced.
This snippet function hashes a string into an MD5. The function will throw an error if an empty string is provided. Just copy and paste this into a console application, set the Sub Main() as the start up object and run it! You will see how the same hash is created for the "Test" string and a different hash is created for the "Test1" string. If you've got any problems with this snippet just comment..