title: role of META-INF directory
body: <p>current spring-mvc webapp <em>(also saw it in another primefaces webapp)</em> webapplication directory structure:</p>
  
  <pre><code>webapp
  |
  |_src
  |
  |_WebContent
    |
    |__WEB-INF
    |
    |__META-INF
       |
       |__MANIFEST.MF
  </code></pre>
  
  <p>Always saw and <code>MANIFEST.MF</code> file in <code>META-INF</code> directory. Some times, it seems nothing else would happen if I deleted them. what's the role of them? </p>
  
  <p><code>~#:cat MANIFEST.MF</code></p>
  
  <pre><code>Manifest-Version: 1.0
  Class-Path:
  </code></pre>