Possibility for creation of Dll file in C#

1)Can u please tell me the possibilities for the creation of dll file in C#

I am aware of it by creating a dll file in ASP

2)How can we change the version of the Assembly & also provide me the detailed info about the Assemblies & the operation performed in it

For the benefit of others, note that this is a duplicate of Possibility for the creation of the dll file in C# Application.