What it means
Hiding turns off a calendar's display in your own view and is easy to reverse. Unsubscribing removes a calendar you do not own from your list; the owner and other subscribers keep their events. Deleting a secondary calendar you own can remove it for everyone who shares it. Google does not let you delete your primary calendar itself, though you can remove its events. These distinctions matter when an unfamiliar calendar seems to be producing spam.
A real-world example
A volunteer sees unwanted promotional entries on a shared community calendar. They first hide it to prove where the entries come from. They are not the owner, so unsubscribing affects their account only. If the owner deleted the calendar to clean their own view, the entire group would lose it.
What to do
Toggle the calendar off, confirm the unwanted entries disappear, inspect ownership, then choose Hide or Unsubscribe as appropriate. Before deleting an owned calendar, consult everyone relying on it and arrange a transfer or export when necessary.
The distinction that matters
Unsubscribing may require the owner or someone with manage-sharing permission to invite you again if you later need access. Hiding leaves the subscription intact. Deleting is a much wider action and should not be used as a quick personal cleanup. Repeated invitations on your primary calendar are not a separate removable calendar; report them as spam and adjust invitation rules. On a managed account, an administrator may control the available actions. Verify the source calendar rather than acting on the first familiar name in the list.
Google Calendar removal options
