I think you might be getting mixed up between the query language and the implementation. Virtual tables define an interface that you can use to write an extension allowing you to query resources using sql semantics. The underlying representation of those resources doesn't change.

So yeah the difference matters depending on your use. I don't think you can add indexes for example, unless they are specifically supported by the underlying resource, or implemented in the virtual table extension you're using.

It's not a table.