In the fairy tale, Hansel and Gretel left a trail of breadcrumbs in the woods so they could find their way back home. The lesson for the Web is clear: people need to navigate back along a path they've already taken. Ironically, though, birds ate their breadcrumb trail in the story, and they got terribly lost. So perhaps the metaphor is not the best one. The term "breadcrumb trail" is widely used in web navigation design nonetheless.
As a navigational mechanism, the breadcrumb trail shows a person's path through a site. It consists of elements, or nodes, that are chained together. The nodes are linked to previously visited pages (or parent topics) and are separated with a symbol, usually a greater-than sign (>), colon (:), or pipe (|).
The most common type of breadcrumb trail generally:
Shows the current position within a site.
Provides shortcuts to previously viewed pages and/or other areas of site.
These are called location breadcrumb trails. In essence, they are a linear representation of a site's structure, e.g., Home > Men's Clothes > Shirts > Dress Shirts. Regardless of how people arrive at Dress Shirts, the breadcrumb trail is the same.
Figure 3-10. Location breadcrumb trail on the NHS web site beginning with ...