Which PHP file to edit for Wordpress Post page?

Hey guys!
Does anyone which php file I must edit for the "articles page"?
In your typical wordpress theme, which PHP file should be edited to edit how the page looks like once your viewing a specific article? thanks

here are list of the PHP files in my theme:

 

single.php

 

Thanks izwanmad!
I had a feeling that was it, just wasn't sure

Appreciate it