Archive is the normal way to retire a record: it hides the patient and keeps the history. Delete exists for a privacy request and takes everything with it, so it's a different decision.
Archive, which is almost always what you want
Archiving marks a patient inactive. They leave the Active list and everyday searches, and their record shows a notice with an Unarchive button, but nothing else changes: appointments, invoices, notes, documents and messages stay exactly as they were, and reports still count them. Use it for anyone who has moved away, finished treatment for good, or died. Find the patient, select Archive in the preview, and you'll see Patient archived.
To bring someone back, filter the list to Archived, select them and choose Unarchive, or open the record and use the button in its notice. There's no bulk archive; it's one patient at a time.
Delete, which can't be undone
Deletion is for a record that shouldn't exist: a duplicate you've decided not to merge, a test patient, a request to erase someone's data. It's deliberately slow to reach.
Archive the patient first
Delete only appears on an archived patient. Trying otherwise answers Only archived patients can be deleted.
Settle their money
A patient with account credit can't be deleted until it's refunded or used: This patient holds 40.00 of account credit. Refund or use it before deleting the patient. Unpaid invoices block it too: Collect or write them off before deleting the patient.
Select Delete and type the patient's full name
The name must match exactly. Then confirm. You'll see Amira Haddad has been permanently deleted.
Deleting isn't the way to fix a duplicate record that has history on it; merging keeps everything under one patient.