Description: Although discovery and
corporate communications have been dominated by email, the
emergence of Unified Messaging Systems deserves consideration when
evaluating metrics of discovery. "Unified Messaging (or UM) is the
integration of different streams of communication (e-mail, SMS,
Fax, voice, video, etc.) into a single, or, unified 'message
store', accessible from a variety of different devices. Unified
messaging is a subset of a fully integrated Unified communications
system."
http://en.wikipedia.org/wiki/Unified_messaging.