title: What do a question mark (?) and an ampersand (&) mean in a URL?
body: <p>I saw a link like this: </p>
  
  <p><code>https://www.google.com/recaptcha/api/siteverify?secret=YOUR_SITE_KEY&amp;response=".$captcha."&amp;remoteip=".$_SERVER['REMOTE_ADDR']);</code></p>
  
  <p>I know that it's setting the secret variable to YOUR_SITE_KEY and response to <code>response=".$captcha."&amp;remoteip=".$_SERVER['REMOTE_ADDR']</code> but, I'm not sure what those symbols means that is, the <code>?</code> and <code>&amp;</code> in the query string. </p>