Could I get a conceptual explanation of the relationship between the public_html and www folders?
I assume that any code change I make in "functions", "header", "footer", etc. PHPs needs to be made and uploaded in both locations.
There have been a few times (and I may have just lost my place) that it seemed that an upload into one changed the other.

this is really a question to ask of your host for your Web site. it doesn't have anything to do with Word Press or Atahualpa.

Having said that, my understanding is that public_html in appache/linux is the directory connected to your account that you have write access to. It is where you do all your work.

WWW is a symbolic link (alias in MS Windows terms) to this directory. You as publisher never do anything there. its is the public face of your site.

This system allows for

ftp://username@hostingcompany.com/public_html

to be represented to the world as

http://www.vanityname.com

-Bill