Chat
Definition:

Free-form, “real-time” communication channels, which may or may not have archives for historical views. Used primarily for “live” discussions, such as online meetings, in an enterprise setting.

Example Usage:

SMS, Twitter

Source: Frappaolo, Carl ; Keldsen, Dan: Enterprise 2.0: Agile, Emergent & Integrated. In: AIIM Market Intelligence (2008), Nr. Q1, S. 90