Again, most breadcrumbs provide not only a navigational aid, but a navigational control as well: They not only show where in the data structure a visitor is, but they give him tools to move to different nodes in the structure in the form of links.

• 而且大多数层级不仅提供了导航帮助，也提供了导航控件。 它们不仅显示用户处于数据结构的什么位置，对于这种链接形式的结构，它们也为用户提供了移动到不同节点的工具。