Trash (sidebar → Trash) holds every deleted task for 30 days. Click Restore on any row, or shift-select multiple and use bulk restore. After 30 days rows are purged permanently.
Archive (sidebar → Archived) holds completed and manually archived tasks with no time limit. Right-click → Un-archive to bring one back to its original list.
Undo shortcut — for anything deleted in the last 5 minutes, Cmd/Ctrl + Z is faster than Trash.
Nothing in Trash? Confirm you're signed into the correct account — Trash is scoped per account, not per device.