What is the difference between cancelling and deleting an appointment?

Cancelling is how you void an appointment: tap it in the Schedule and press "Cancel appointment". Before doing it, it tells you whether the client will get the cancellation notice ("María will get a cancellation notice") or whether there is no way to reach them ("María won't get any notice: let them know yourself if needed"). The slot is freed immediately and the appointment stays in their history as cancelled.

Deleting ("Delete appointment") is only for undoing a mistake you made when booking it. It shows on the appointments you entered yourself from the dashboard, by hand or with a pass, while they are still pending or confirmed. It is deleted for good, along with its history, and nobody is notified. A booking the client made (on your website, in "My appointments", over WhatsApp…), an imported appointment, or one that is already cancelled or closed cannot be deleted: it is cancelled, or corrected with "No show" or "Reopen". That way nobody turns up holding a confirmation for an appointment that has vanished.

Cancelled appointments take no room in Today or Plan. To see them, go to the Search tab, choose "All" and filter "Status: Cancelled". If you cancelled by mistake, open the appointment and press "Reopen".

Imported appointments are undone from their import, in Clients › Import & export data, during the following 24 hours.