What is documents and data in iPhone Storage?

I read that it is the junks files including browser history, cookies, logs, caches of photos and videos, database files that are stored by your apps.
Someone suggested downloading something that would "clean" your phone and free up space on your phone.
I did this, but it only gave me the smallest amount of space available and I was hoping for much more!
Can anyone help me out?

This article can help you.
http://www.fireebok.com/resource/how-to-delete-documents-and-data-on-iphone.html