Actually, WordPress doesn't use any "element" - with the exception of some lists that are displayed in the sidebar, usually: wp_list_pages, the categories list, blogroll list.
All the rest of the div classes and ID, or paragraph classes etc. are defined by the theme author. In this case - YOU.
Let me give you an example: according to the Codex this might be the sinplest Loop for an index.php file -
<?php
get_header();
if (have_posts()) :
while (have_posts()) :
the_post();
the_content();
endwhile;
endif;
get_sidebar();
get_footer();
?>
OK, now disregard the call for header, sidebar, footer... and you end up with this:
<?php
if (have_posts()) :
while (have_posts()) :
the_post();
the_content();
endwhile;
endif;
?>
Everything you are going to add, i.e. Template_Tags like
the_title
the_date
the_permalink
the_category
can and should be wrapped inside divs and/or other html tags. The name and the properties of those divs will be defined exclusively by you. It makes sense to call the div where the_content goes as div class=entry or "post" or "blogpost"... but you can call it "stuntmusic" or "moshu" as well.