Before items are deleted they might end up in a user's trash. The trash can be managed by a user through any of the Box apps, and by an application via the API.
Two-stage Deletion Process
Box uses a two-stage process to remove or trash files, folders, and web links before permanently deleting them.
By default, items can be restored after they are trashed within a 30 day time frame before they are purged. The purge window can be modified by an enterprise administrator.
More details can be found in the Box community article on Managing Trash