title: PHP and MySQLi close()
body: <p>I am new to MySQL and PHP and am attempting to make my own CMS to help make managing my websites easier. Can someone explain mysqli's <code>close()</code> function?</p>
  
  <ol>
  <li>Is it necessary? </li>
  <li>What exactly does it do?</li>
  <li>I heard that after PHP runs its script that it closes the
  connection, is that true?</li>
  <li>Lastly, is there a security issue when not closing your connection
  to the database?</li>
  </ol>