Wordpress File Structure

I need some help understanding Wordpress's file structure or the URL structure. Not the Template Hierarchy, I understand that. What i mean is how a websites files are set up according to it's URL.

Example:

Lets say I have a website named Country.com which lists information "About" the country and a map to it.

So Lets say I'm at country.com/usa and on the country page of USA I see a link to obtain information on the about as well as a link to go to a page with a map.

Now here is the question, in regular html and css websites each time you see a forward slash it means it's a new folder. country.com/usa usa being the new folder. Now what would USA be in Wordpress? would it be a post? a page? archive?

So the URL would look like this for the example.

country.com/usa

country.com/china

country.com/france

Then on each of those directories they have their own about page and map page.

So:

http://ift.tt/1DmPGoM

http://ift.tt/1wmbHo8

http://ift.tt/1DmPGFc

I guess a better way and more straight forward way of asking is what are those directories specifically. What template files would I be using to get /about for each country.

So if china is a page then what would the /about be? another page or post?

I am just confused on the "files or url" structure and how people make 1 page contain 10 different directories like,

http://ift.tt/1wmbFwz

really confused as to what all the directories /folder/folder/folder and what files they are using for that. Is it Post, Custom Post Type, Archive, Single? Can someone please elaborate.