Time-stamp is a real-time measure of the time of a trigger event. The time-stamp is available in the record header. Time-stamp start point is determined by the user through a reset command. The pace of the time-stamp counter is set by the clock of the digitizer. 

Trigger event is an external signal that activates the data acquisition. This can be a dedicated trigger signal on the trigger input connector, a software command, or an event on the analog signal.