List and describe the three main information system architectures

What will be an ideal response?

An information system architecture is important because it describes how computing resources will be accessed and shared throughout the organization. This is especially important for the design of the integrated information systems. Originally, users had to connect to a mainframe computer with a variety of terminals in what was a very centralized IS architecture. With the advent of personal computers on everyone's desktop, computing became very decentralized since they had limited connections to other computers. Eventually, these personal computers were all linked up together in Client/Server networks in what is now known as a distributed IS architecture. This current model provides huge improvements in speed, power and access to data and applications, and does so for lower costs.