Registration information is required to put your Server Scriptlets to work as a real COM object. Basically, it allows any COM server to be retrieved and invoked by clients at run-time. There are two fundamental pieces of registration information—a ProgID and a CLSID. Both of these allow any client application to get in touch with the server and work with it. This information must be public and stored in an easily accessible location Under the Win32 platform this is the system registry.
A ProgID is a string usually composed by two or more words separated by dots. When you use the VBScript's
function to instantiate a new object, what you are actually doing is passing it a ProgID string. A COM server is uniquely identified by a number called CLSID. The CLSID is what you're requested to indicate when using ActiveX Controls in your HTML pages.CreateObject
Even when the function you're using requires a ProgID then it gets translated into the corresponding CLSID. In a previous figure, we presented a screenshot of the Windows registry where a given ProgID entry had its own CLSID key.