Using CLS instead of dll in Visual Basic

I've seen in several places that you should create a CLS file in Visual Studio 2010 instead of a dll file. I see how a windows application can get use a CLS file, but I am writing an extension for a program that is looking for dll f开发者_如何转开发iles. Is it possible to create a dll in Visual Studio 2010. If not, is there a difference between using a dll vs. a cls as an extension

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I only know the .cls extension as a VB6 class type source file and have heard of compiled java cls files. For interest sake, where have you seen that you should create CLS files in VS2010 instead of dlls?

Of course it's possible to create a dll in Visual Studio 2010. As in previous versions, dlls are Class Library assemblies. When you compile a Class Library project, you get a dll.You can also still check an option to 'Register for COM interop', which means you'd be able to use your dll with older applications built in VB6 for example, provided the interops are generated correctly.