SharePoint’s Recycle Bin
SharePoint Server and SharePoint Online have built-in mechanisms to protect against accidental deletion of content.
They both have a recycle bin per Site Collection.
On-premise, by default, deleted items are kept for a configurable 30 days.
Online, however, these settings are configured for you and can’t be changed. Deleted items are kept for 93 days before they are removed.
Both on-prem and online split this bin into two parts: the Recycle Bin, and the Second Stage Recycle Bin for administrators and owners.
There has always been a lot of confusion about what Second Stage actually means.
But, what magic is it that moves a deleted thing from Stage One to Stage Two?
Does it move by itself 30 days after deletion?
Well, up until SharePoint 2016, this second bin was also labelled “Deleted from end user Recycle Bin”. And that’s the clue.
There is only one action that moves deleted items between stages: when a user deletes an item from their recycle bin.
Instead of getting completed deleted, it moves to the Second Stage bin, where an administrator or owner can restore it.
Whichever bin the item is in, after 30 days, or 93 online, it will be deleted.