“Breadcrumbs” are a kind of secondary navigation that shows all the previous pages in the tree before this one. On larger sites it helps to give the user context about where they are – particularly helpful if they arrived at inner page on your site via a Google search or direct link.
The Bedrock Breadcrumbs Widget allows you to place a breadcrumb trail on your pages. If you have a widget visibility plugin installed you can choose to only show breadcrumbs on some pages.
You can opt to show the current page in the breadcrumb and also decide if you want to show the homepage at the “root” of the breadcrumb and if so, what it should be called.