Virtual Directories?

[Jerry M]

I've just started looking at the apache ftp server.  The docs mentioned 
virtual directory support.  But I couldn't find anything in the docs 
related to how to set it up and what the capabilities are.

I'm running a Windows server.  Is there a way to let user A have access 
to folders X, Y, Z and user B have access only to folder Y, etc?  How is 
that configured?

Did I miss a section of the docs where this is covered?

Thx.