So the table (or seed) is acting sort of as a template for the information added via AJAX?
Each AJAX call to get the animal sound is nested inside the original AJAX call that gets the list.
a refers to the request variable name and n is the value
Even though ajax has a strict same domain policy. We can set header information (as the code does in Animalia.php) to allow access from all origins. This is a site talking about this in more depth click here.