The respondent to a civil court case is the person who first received a notice of summons and therefore is required to file their appearance in order to schedule their first court date. The person who originally filed the summons and the original petition is called the petitioner to the case.  

The petitioner and respondent to a case will continue to be the petitioner and respondent throughout the duration of the case, EVEN WHEN the respondent files a notice of motion – remember this when filling out any paperwork that asks you to list the names of the petitioner and respondent.