Some doubts about how the loop work (trying debugging it)

<?php
if (have_posts()) : while (have_posts()) : the_post();                                     endwhile;
 else:
 _e('No blog found.', 'polymer');
endif;
?>

if(have_post) condition is to check if the page contain post, while(have_posts) condition if there is more than one post display in loop, the_post() is used to display the post if(have_post) condition fails it will go to else loop. Tell for any further doubts…..