Syncing Exchance calendar with iCloud

[davidra]

Even after a number of years, I don't quite get the calendar/sync process. My primary calendar for iPad, iPhone and iMac is my Exchange account from work. I have now retired and would like to move everything to iCloud and have it serve as my primary calendar. Three iCloud calendars and three Exchange calendars show up on my iMac. I have set iCloud to sync calendars. However, when I go to the calendar on iCloud, it's empty. I always assumed that iCloud would sync with whatever I was entering into the iMac and other devices. Is it just that iCloud is backing up the calendar content, but not syncing it? Sorry for such a basic question....but I can't figure this out.