title: <button> vs. <input type="button" />. Which to use?
body: <p>When looking at most sites (including SO), most of them use:</p>
  
  <pre><code>&lt;input type="button" /&gt;
  </code></pre>
  
  <p>instead of:</p>
  
  <pre><code>&lt;button&gt;&lt;/button&gt;
  </code></pre>
  
  <ul>
  <li>What are the main differences between the two, if any?</li>
  <li>Are there valid reasons to use one instead of the other?</li>
  <li>Are there valid reasons to use combine them?</li>
  <li>Does using <code>&lt;button&gt;</code> come with compatibility issues, seeing it is not very widely used?</li>
  </ul>