[itsm] response time

Hi Expert   The below display the right panel of OTRS, may i know which action will actual update the time ? i.e. if i do a Note at first time response of ticket, would it stop clocking on response time   First Response Time: -20 minutes 03/08/2009 16:08 Update Time: -20 minutes 03/08/2009 16:08 Solution Time: -20 minutes 03/08/2009 16:08