and data storage and access are developed and maintained as
Apart from the usual advantages of modular software with well
defined interfaces, the three-tier architecture is intended to
allow any of the three tiers to be upgraded or replaced
independently as requirements or technology change. For
Typically, the user interface runs on a desktop
PC or
functional process logic may consist of one or more separate
the data storage logic. The middle tier may be multi-tiered
itself (in which case the overall architecture is called an
"n-tier architecture").
(1998-05-13)