VERTICAL MENU
Jacob Nielsen claims that CNET.com was the first to make extensive, consistent use of a navigation mechanism (a stack of links on the screen's left) across an entire site. Called a vertical or left-hand menu (or right-hand menu if on the right), this vertical arrangement has become prevalent in web navigation design.
Vertical menus are generally more flexible than navigation bars or tabs. Because the mechanism can easily extend downward, adding options is usually not as problematic as adding a tab. Additionally, vertical menus generally allow for longer labels, particularly if they can wrap onto two or more lines.
The Oracle web site uses a vertical menu with long, descriptive labels on the left of its home page to provide access to the major areas of the site (www.oracle.com, Figure 3-31). In a horizontal navigation bar, many of these labels would have to be shortened.

Figure 3-31. A vertical menu of the left side of Oracle.com
Vertical menus can also appear elsewhere on the page, such as for related links further down or for adaptive navigation, both discussed further in Chapter 4.