A Menu Bar widget is a set of navigational menu buttons that display submenus when a site visitor hovers over one of the buttons. Menu Bars let you display a large amount of navigational information in a compact space, and also give visitors to the site a sense of what is available on the site without having to browse it extensively.
Dreamweaver lets you insert two kinds of Menu Bar widgets: vertical and horizontal. The following example shows a horizontal Menu Bar widget, with the third menu item expanded:

