The breadcrumb shows you where in the hierarchy you are:

>Study at York>Undergraduate study>Applying 
<div class="c-breadcrumb">
  <div class="c-breadcrumb__items">
    <a href="/"><i class="c-icon c-icon--home"></i></a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/">Study at York</a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/undergraduate/">Undergraduate study</a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/undergraduate/applying/">Applying</a>
  </div>
</div>

If the bread crumb becomes unmanageably large (I'm talking to you, departmental pages), especially on mobile, we close it up so only the home, level 1, level n-1 and level _n_ items are shown. Clicking on the ellipsis expands the rest of the breadcrumb items.

>Chemistry>About staff>Academic staff>T to Z>Professor Richard Taylor>Taylor Group Pages>Photo Gallery>Former Groups 
<div class="c-breadcrumb is-closed">
  <div class="c-breadcrumb__items">
    <a href="/"><i class="c-icon c-icon--home"></i></a><span class="c-breadcrumb__separator">&gt;</span><a href="#">Chemistry</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">About staff</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">Academic staff</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">T to Z</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">Professor Richard Taylor</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">Taylor Group Pages</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">Photo Gallery</a><span class="c-breadcrumb__separator">&gt;</span><a href="#">Former Groups</a>
  </div>
</div>

There is also a JS fix which removes the last item if it is called "Header".

>Study at York>Undergraduate study>Courses>Header 
<div class="c-breadcrumb">
  <div class="c-breadcrumb__items">
    <a href="/"><i class="c-icon c-icon--home"></i></a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/">Study at York</a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/undergraduate/">Undergraduate study</a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/undergraduate/courses/">Courses</a><span class="c-breadcrumb__separator">&gt;</span><a href="/study/undergraduate/courses/header/">Header</a>
  </div>
</div>