We can gzip our site page with apache and php. Is there any difference between them?
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How can we handle compression in both? Whose responsibility is it? Which one is better, using apache or php to compress files?  
PHP compression code:  

    ob_start("ob_gzhandler");

Or the apache one:

    AddOutputFilterByType DEFLATE text/html text/plain text/xml 

Is this right that requests first reach in apache then to PHP? If answer is positive so can we infer that we should use the apache one?