Breadcrumb
A breadcrumb shows where a page sits. It is a <nav> labelled Breadcrumb holding an ordered list, so the trail reads in order and the last item is the current page.
<nav aria-label="Breadcrumb">
<ol>
<li><a href="./">Home</a></li>
<li><a href="components/">Components</a></li>
<li aria-current="page">Breadcrumb</li>
</ol>
</nav>A trail
The <ol> lays the steps in a row with a separator between them. Each step before the last is a link.
<nav aria-label="Breadcrumb">
<ol>
<li><a href="./">Home</a></li>
<li><a href="components/">Components</a></li>
<li><a href="components/structure/">Structure</a></li>
<li aria-current="page">Breadcrumb</li>
</ol>
</nav>The current page
The last item drops the link and takes aria-current="page", so it reads as where you are.
<nav aria-label="Breadcrumb">
<ol>
<li><a href="./">Home</a></li>
<li aria-current="page">Here</li>
</ol>
</nav>