What are 'breadcrumb' links?

This is a navigational aid in web pages. In Figure 1, I have gotten to the last page on a shopping site and the highlighted region is where you find the 'breadcrumbs'. One step back (which you can reach by clicking on that particular crumb[Brand:Acer Comuter]) will bring you back to the page pointing to that crumb, Figure 2.

Figure 1

Figure 2