h the <code>photo</code>
template. If the user goes back and clicks on a different photo, we want
to display the <code>photo</code> template again, this time with a different model.</p>
<p>In cases like this, it's important that we include some information in
the URL about not only which template to display, but also which model.</p>
<p>In Ember, this is accomplished by defining routes with <a href="../defining-your-routes/#toc_dynamic-segments">dynamic
segments</a>.</p>
<p>Once you have defined a route wit