NodeList is not an Array, you can iterate over it with forEach(). It
can be converted to a real Array using Array.from().
There are 2 varieties of NodeList: live and static.
Live NodeLists: changes in the DOM automatically update the
collection. For example, Node.childNodes is live.
Static NodeLists: any changes in the DOM does not affect the content
of the collection. The document.querySelectorAll() method returns a
static NodeList.