To remove content from a live site, pages and files must be moved to the Recycle Bin. Pages that are moved to the Recycle Bin can be restored, if necessary. When a page is recycled the published content is automatically removed. Once a page is deleted from the Recycle Bin or a folder is deleted, it can no longer be retrieved.
If you are removing an entire folder, you should first recycle all content items within the folder then delete the folder itself. If you delete the folder it will delete all items within it and that content will not be able to be restored.