Help Understanding Category Structure Code Help

Hi,

I’m trying to see how categories work together, and wondered if you could see if i’m doing this right.

I’m creating a portfolio website and need the structure like this:

(My permalink structure is “/%category%/%postname%/”

Parent Category: mysite.com/portfolio/
Child Category: mysite.com/portfolio/photography/
Single Post Entry mysite.com/portfolio/photography/single-post-url

Child Categories can not be hard coded, e.g. category_photography.php

So I need code that says something like:

If Category is a “Parent” then show this code…. else…. Show the children code….

All this is within category.php….

Hope someone can assist.