title: getenv() vs. $_ENV in PHP
body: <p>What is the difference between <code>getenv()</code> and <code>$_ENV</code>?</p>
  
  <p>Any trade-offs between using either?</p>
  
  <p>I noticed sometimes <code>getenv()</code> gives me what I need, while <code>$_ENV</code> does not (such as <code>HOME</code>).</p>