title: Difference between mod_deflate and zlib output_compression
body: <p>Can anyone tell me the difference between using mod_deflate and zlib output_compression?</p>
  
  <p>I understand that zlib is done in PHP and mod_deflate is done in Apace, my .htaccess file looks like:</p>
  
  <pre><code>php_flag zlib.output_compression On
  </code></pre>
  
  <p>or:</p>
  
  <pre><code>SetOutputFilter DEFLATE
  BrowserMatch ^Mozilla/4 gzip-only-text/html
  BrowserMatch ^Mozilla/4\.0[678] no-gzip
  BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html
  SetEnvIfNoCase Request_URI \
  \.(?:gif|jpe?g|png|gif)$ no-gzip dont-vary
  Header append Vary User-Agent env=!dont-vary
  </code></pre>
  
  <p>Advantages/disadvantages of either?</p>