For any view which does not have a different format record, WordPress will utilize index.php as a matter of course. On the off chance that a guest demands a solitary post, WordPress will initially search for a record named single.php. In the event that that record exists, it will be utilized to introduce the post to the guest. On the off chance that that record does not exist, WordPress will utilize index.php to display the post to the guest. This is known as the Template Hierarchy.