What is ICS? Marek Hrycak March 26, 2019 08:39 Updated Follow The "ICS" file contains information related to calendars. Related articles What is iCalendar? What does the abbreviation URL mean? What does the abbreviation OTA mean? What is "iCalendar" (iCal)? Why is it necessary to log in to my Google account in order to integrate with iCalendar? Comments 0 comments Please sign in to leave a comment.