ABSTRACT
In general, in particle physics interesting events and the response they produce in detectors are instantaneous, or they have a very short duration given by decay lifetimes. This duration can be increased by the finite response time of the detectors, but is still very short compared to the operational time of the experiment. Other events, from interesting physics or backgrounds, will take place before and after, and thus, in general, the experiment will need to identify the occurrence of specific events in time and record the information from its detectors for this instance. This identification is provided by the trigger.
