Acknowledgement

1. A response sent by a receiver to indicate successful receipt of a transmission.

Note: An example of an acknowledgement is a protocol data unit, or element thereof, between peer entities, to indicate the status of data units that have been successfully received.

2 . A message from the addressee informing the originator that the originator's communication has been received and understood.

Source: from Federal Standard 1037C and adapted from the Department of Defense Dictionary of Military and Associated Terms