IS control is a COM object that a server/site administrator can use to add virtual directories to IIS. It can be used to create a full domain or create a virtual directory on a domain with a couple of lines of ASP code.
It can also be used to set the R,W,E,F permissions on a directory or file for a specific user. Uses include adding a virtual directory with IUSR_somname having read only permissions on a folder so a server administrator can give individual websites rights to read information from one instance of data on the server.