The grace period enables you to prevent creating a large number of tickets for frequently created incidents due to reoccurrence of the same event.
For recurring incidents, the grace period is a time period during which reoccurrences of the same incident update (or reopen) an existing ticket for the incident instead of opening a new ticket.
For example, an incident triggers and a ticket is opened for it. If the grace period is one hour and the incident is cleared at 10:00 a.m., and if the same incident retriggers before 11:00 a.m. (one-hour grace period), the ticket that had been originally created for the incident is updated/reopened rather than creating a new ticket.