Second Stage Recycle Bin - When an item is deleted from a site's Recycle Bin it goes to Site Collection Recycle Bin and stays there until you restore it or the retention policy expires (deleted after a set number of days, by default it stays for 30 days) or you delete it from there also in which case it gets deleted permanently. The items from the Site Collection Recycle Bin can be restored by a Site Collection Administrator. You can view the Site Collection Recycle Bin by clicking on the Recycle Bin link under Site Collection Administration on Site Settings page. This page has two views: End User Recycle Bin Items view displays all the contents of all the recycle bins of all the sites under that particular site collection whereas Deleted From End-User Recycle Bin view displays all the items which have been deleted from the sites recycle bins and now exist in site collection recycle bin.