A classifier is a set of rules that identifies a device type based on the results of a probe. A classifier
can have one or more related lists that define the classification criteria, the pattern probes, and the
triggers probes. The pattern probes related list specifies which horizontal discovery pattern to run for
the device type. The triggers probes related list specifies which probes to run after the device is
classified, and before the horizontal discovery pattern is executed. The triggers probes can be used to
gather additional information or credentials that are needed for the horizontal discovery pattern12.
Reference:
1: ServiceNow Discovery Overview, page 9
2: ServiceNow Discovery Documentation, Classifiers section
