Editing content with views
You are basically right regarding views. Views is a way to see data aggregated together in some fashion. Think visual SQL. 

The original request seems a bit confusing to me. I think you are asking for 2 things. Theming the content based on type as well as theming the views output. 

For content type, take a look at theming nodes by content type . Drupal 6 and 7 are different in the way they go about this but for drupal 6 you are more or less looking to use the template node-[NODETYPE].tpl.php. This will adjust your node's output on a full view.

For theming your view, take a look at your view in the edit mode. Under basic setting you will see Theme: Information. Click on that and you will get a listing of possible templates that you could use to theme your view. Generally the same way you would edit your node type template you would edit your views template file. Check Theming Views for more info.