A tree menu is a menu which displays a hierarchy of items which can be expanded or collapsed at the viewer's convenience. Many of the browsers used to manage file systems on a hard drive are in the form of tree menus, allowing people to click buttons to expand various folders within the file system to see what's inside, and a cascading effect can be created with numerous branches of the menu nestled inside of each other. This type of menu can also be used on a web site which wants to present information in an organized fashion.
Tree menus are useful for several reasons. Because they can be collapsed and expanded, they can be used to display a lot of information without overwhelming a viewer. For example, a travel site could have a tree menu with the top-level headings “Asia,” “Africa,” and “South America,” and when someone clicked the button to expand “Africa,” a list of subheadings like “Southern Africa,” “Equatorial Africa,” and “Northern Africa” could appear, with each subheading containing subheadings for various nations which could be expanded into regions, cities, and so forth. The alternative would be to display a huge menu which would be daunting to navigate and would display unnecessary information; someone who wants information about the Great Wall of China, for example, doesn't need to see information about Egypt.
People can also use a tree menu to explore the relationship between various items on a list. People with highly organized file schemes appreciate tree menus because the menu allows them to create a series of more precise categories for their information, from a broad topic like “pictures” to a more specific one like “Hawaii Trip.” Tree menus also make it easy for people who are not familiar with the information to navigate it, because the presentation is clear and easy to understand.
On websites, a number of programming languages can be used to create tree menus. Flash and a number of scripts can be utilized to make flashier tree menus, and tools like PHP and HTML can also be used, depending on the desired look and feel of the menu and the level of skill of the programmer. Several companies sell dynamic tree menu code which people can simply drop into place, and free versions are also available.
Many software programs which organize bulletin boards, files on an FTP site, and so forth use tree menu schemes to present information. Users may be presented with several different options including a “tree view,” and they can select the viewing version which they feel more comfortable with.