Difference between theme preprocessor & processor function? The question is is self-explanatory!

Another question, suppose I have a template file named a-b--c--d.tpl.php

What would be the preprocessor function for this template file? I suppose themename_preprocess_a_b__c__d(&amp;$vars)? 

Sorry for my poor knowledge. I'm newbie to drupal &amp; started with drupal 7.
For the template

If the page is "/my-node", the page template will be "page--my-node.tpl.php".

For the Prepocess

But you cannot using it "themename_preprocess_my_node(&amp;$vars)" because my-node isn't a hook ! You can find differents hooks with this page http://api.drupal.org/api/drupal and with the search box,  type 'theme_'. You can see the differents hooks for the preprocess