Decoding the web.config httpmodules

I recently started learning about HttpModules and made my first开发者_如何学编程 one. I was wondering if someone could explain why some modules in the the web.config include a lot of extra info and others do not.

example: not much info

<add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah"/>

example a lot of info

<add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>

What is a publickeytoken, version, culture. Do I need to do anything special to use those?

Thanks!

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These are part of the assembly's fully qualified name.

Version should be self-explanatory.
Culture is the culture that the assembly was compiled for.
PublicKeyToken is a value that is cryptographically derived from the key used to sign the assembly, or (null) if the assembly is unsigned.

For more information, see here.