What is ICS? Permanently deleted user March 26, 2019 08:39 Updated Follow The "ICS" file contains information related to calendars. Related articles What does the abbreviation URL mean? What is "iCalendar" (iCal)? What is iCalendar? What does the abbreviation OTA mean? Which data are synchronized via iCalendar? Comments 0 comments Please sign in to leave a comment.