title: Does using REFERENCES without FOREIGN KEY still create a foreign key?
body: <p>I have done some SQL before but not loads. I am a bit confused about what REFERENCES does if you use it without FOREIGN KEY when creating your table e.g.</p>
  
  <pre><code>author_id INTEGER REFERENCES users(id),
  </code></pre>
  
  <p>As opposed to...</p>
  
  <pre><code>FOREIGN KEY (author_id) REFERENCES users(id)
  </code></pre>
  
  <p>If these are different what is the difference? And if they are the same which form should be preferred?</p>