PHP script execution mode
This option determines if PHP scripts are run as the Apache web server user (typically httpd or apache), or the Unix user who owns the virtual server. The former is faster as it means that no additional processes need to be started to execute PHP code, but less secure as scripts read and write files as a user other than the domain owner.

If your system supports it, the FCGId option is the best, as it runs PHP scripts quickly and as the domain owner. Otherwise, unless your system is heavily loaded or security between users is not an issue, the CGI wrapper option is recommended.