Where can we get the definition for the following fields? How are these fields derived? (e.g. _num_events)
In a user audience, there are some fields that is not related to any data stream (these were not custom defined fields as the "stream" value is blank).
I can't find in the document what each of these fields mean or how are they derived. Can anyone shed some clarity for each of the said fields? The field names seems to infer important values but unless there is a relevant reference, the use seems to be speculative at best.