This article explains the two-stage recycle bin in SharePoint.
IntroductionLooking for the Recycle Bin in SharePoint 2013? You won't find it in its previous location (Quick Launch with the All Site Contents).In a SharePoint site, the Recycle Bin provides temporary storage for all items deleted from that site. The Recycle Bin can be accessed from the following the Quick Launch Bar on the left of the screen. SharePoint offers a two-stage Recycle Bin so items that are deleted from the end user Recycle Bin may still be recoverable from the site collection Recycle Bin by a site collection administrator.First StageThe Recycle Bin is accessed. On the SharePoint site, click Site Settings and select “Site Contents”. The link is then available from the “Site Contents” page. Alternatively, this can be accessed by adding “/_layouts/15/Recyclebin.aspx” or “/_layouts/15/viewlsts.aspx” to the end of your site's root URL.Second StageThe Second Stage Recycle Bin is available to site collection administrators only and can be access from “Site Actions” > “Site Settings”. Alternatively, this can be accessed by adding “/_layouts/15/AdminRecyclebin.aspx” to the end of your site's root URL items.Go to the Site Collection Recycle Bin:As a site collection administrator, I go to Site Actions (or the gear) Site Settings in order to get to the Site Collection Recycle Bin link. Click the Site Collection Recycle Bin link as in the following:When I click on the Recycle Bin link in the Site Collection Administration section of the Site Settings page I am taken to the Site Collection Recycle Bin page. Go to the Site Collection Recycle Bin as in the following:From here I can see all the items that have been deleted and are sitting in the first stage or end user Recycle Bins, as well as those that have been deleted from those locations and are now sitting in the second stage Recycle Bin. I click the link "Deleted from end user Recycle Bin".
SharePoint Online And Office 365 Administration