event.preventDefault() prevents the default behavior of an element from occuring. For example, links automatically brings you to the page that is linked. If you call this right after the click event of an anchor tag then the default behavior won’t occur, event.stopImmediatePropagation() prevents the rest of the events from being executed and prevents it from bubbling up the DOM tree, event.stopPropagation() prevents the parent elements from catching the events binded to a child element. You might have noticed that when you just binded an event to a child element the event is also triggered by their parents. event.stopPropagation() prevents this from happening.

namespacing events event.namespace this is used to separate other from each other. This is a nice way to organize code.

You can actually specify a title attribute to a label or any element to act as a tooltip.