The second tier is the business logic. It is independant from
the frontend (first tier) and backend (thrid tier).

You could write a 3-Tier application using VFP or VB\Access.

Client-server on the other hand is the processing of the data
by a backend database server. It doesn't send back the entire
table (or index), the server just sends back the exact request.

If you call\update\add data directly from a front-end such as
VFP, that is using client-server not 3-Tier.

>Thanks Jim,
> But why wouldn't Client-Server be considered a 2 or 3 Tier? Maybe I don't understand C/S either. I just thought it was an utility that brings data off a server to a local front-end interface for the user?