SQL SERVER Runtime Edition License and Full Sql License



Could anyone please help me on the below required information.

What is Sql Server Runtime Edition license.

If I don't have a SQL License of any type, would i be able to run Microsoft SQL Server option for Navision. If no, then what would i need to do making the SQL Server option run.

As per the application developer's guide -

To install a stand-alone client for SQL Server, you must install the Microsoft SQL Server

Express along with the client. This installs a local instance of SQL Server and attaches a

demonstration SQL Server database to the server. When you start the client, it

automatically opens the demonstration database.

Is that SQL Server Express available in Navision CD.

Can I use SQL Server Express edition for Production system without license. 


Can I use SQL Server Express edition for development/testing navision system without license.  


I have asked a no. of questions but if anyone could answer it, his cooperation will be highly appreciated and thanks heaps in advance.