The HTML DOM NodeList Object
A NodeList object is a list (collection) of nodes extracted from a document.
A NodeList object is almost the same as an HTMLCollection object.
Some (older) browsers return a NodeList object instead of an HTMLCollection for methods like getElementsByClassName().
All browsers return a NodeList object for the property childNodes.
Most browsers return a NodeList object for the method querySelectorAll(). Continue reading JavaScript HTML DOM Node Lists