title: Capitalization of font names in CSS / HTML required?
body: <p>I've been doing the codecadmy lessons on HTML / CSS and I'ma bit confused by capitalization.  It tells me always to remember to capitalize the font name but other times it's examples will show it lowercase.  For example codecadmy shows these examples as a guideline:</p>
  
  <pre><code>p {
      font-family: Tahoma, Verdana, sans-serif;
  }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>h1 {
      font-family: Times, serif;
  }
  </code></pre>
  
  <p>Why is <code>Tahoma</code>, <code>Verdana</code>, and <code>Times</code> capitalized while <code>serif</code>, and <code>sans-serif</code> are lowercase?  Seems odd.  </p>
  
  <p>Thanks</p>