Application Protocol Data Unit
Also found in: Acronyms.
Application Protocol Data Unit
(networking)(APDU) A packet of data exchanged between two
application programs across a network. This is the
highest level view of communication in the OSI seven layer model and a single packet exchanged at this level may
actually be transmitted as several packets at a lower layer as
well as having extra information (headers) added for routing
etc.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)