"Client/server" is now a somewhat tired buzzword in the computer industry, but it is still mentioned frequently in the press. You'll find an excellent overview of client/server computing if you visit the Software Technology Review's Client/Server Software Architectures page at www.sei.cmu.edu/str/descriptions/clientserver_body.html. (The Client Server Group Web site at www.isa.co.uk/csg is no longer available.) For information about 2-tier, 3-tier, and N-tier client/server architecture, connect to www.ilt.com/AEDIS/Ntier. You'll find a brief overview of the advantages of N-tier architecture at www3.sympatico.ca/jwoodger/archmult.htm (www.buzzeo.com/zeologixNTier.html is no longer available). The book Building N-Tier Applications with Com and Visual Basic 6.0 by Ash Rofail and Tony Martin (John Wiley & Sons, 1999) presents the step-by-step process of building an N-tier application.