Much of this improvement is derived from making many applications and systems work together. However, with today's technology smooth interaction of different applications requires complex system implementations. Think about your Mac spreadsheet retrieving information you need from a PC in California accessing a UNIX database on a server. To accomplish this, you use many underlying technologies, including several operating systems and local area networks, a wide area network, messaging protocols, and a database management system.
Architecture is a set of agreements about information technology interfaces and products.
In its simplest form, it describes standards. Widespread agreement on standards leads to the design and purchase of interoperable systems. It needs to suggest workarounds when interoperability fails. It needs to inform purchasers and developers about the larger context in which their systems must work. It needs to encompass a process for reaching agreement.