Html Collection
The HTML collection is a dynamic list. It is live and it reflects changes as they are made. It only returns the specific elements that are called. Items within the HTML collection can be accessed by their name, id, or index nymber.
NodeList
The Nodelist is a collection of objects that is static most of the time. It does not reflect changes as they are made. It returns elements, classes, and the text contained within them. Items in the nodelist can be accessed by their index.
Similarities and Differences
Both are like an array and a count of the items within them can be found using the length property.
Summary
Html collections and nodelists are very similar, but they have different available properties. Both are accessed for different purposes in Javascript.