Information Architecture
Information architecture is the term used to describe the structure of a system, i.e the way information is grouped, the navigation methods and terminology used within the system.
An effective information architecture enables people to step logically through a system confident they are getting closer to the information they require.
Most people only notice information architecture when it is poor and stops them from finding the information they require.
Information architecture is most commonly associated with websites and intranets, but it can be used in the context of any information structures or computer systems.