Plain English Meaning
A wireless connection that lets two computers send information to each other -- in this case, sending traffic data from a radar on the ground up to your aircraft.
Full Definition
A digital communication channel that transmits information between two systems, such as between a ground-based radar facility and equipment on board an aircraft. In the Traffic Information Service context, the data link carries traffic position and altitude information from a ground radar to the aircraft's cockpit display.
Context Anchor
Seen in Traffic Information Service discussions, especially when cockpit traffic displays depend on information sent from ground equipment.