event-flow

Why does a book say DOM event flow has both Capturing and Bubbling? Then won't the event occur twice?

The book Professional Javascript by Zakas says that 1) IE uses event bubbling 2) Netscape uses event capturing 3) DOM event flow is first capturing and then bubbling So, won't the event handler be called twice? What is this DOM event flow, is it the DOM level 2 event handling? As I understands it, is the following true? a) IE 6, ...

What is a good example to listen to event both at the "link" (or div) and at the parent or ancestor element?

Most of the time I see code registering an event listener for a link or a div or button, and handle everything from there. But the event capturing and bubbling is good to handle events at the offspring and then at the ancestor level. But what is a good example we will want to listen at 2 different places? ...