presents a fixed model, we don't need any
additional information to know what to retrieve.  However, if we want a route
to represent a single post, we would not want to have to hardcode every
possible post into the router.</p>
<p>Enter <em>dynamic segments</em>.</p>
<p>A dynamic segment is a portion of a URL that starts with a <code>:</code> and is
followed by an identifier.</p>
<div class="filename javascript"><div class="ribbon"></div><span>app/router.js</span><pre class="language-javascript line-numbers"