What is the difference between DOM Level 0 events vs DOM Level 2 events?

What is the difference between DOM Level 0 events vs DOM Level 2 events? I ask because I was told that Firefox and IE call them in a different order and I had never heard those terms before.

Answer

DOM Level 0 events were based around the concept of using element attributes or named events on DOM elements, e.g.:

<input type="button" onclick="clickMe();" />

Or

input.onclick = function() { ... };

With DOM Level 2, we’ve now got a more standardised approach to managing events and subscriptions, with addEventListener, removeEventListener, etc.

You can read more here here

It wasn’t until IE8 that Microsoft added support for the W3C standard for event management to their browser. Not sure in what order they are called….