How To Install And Configure mod_deflate On CentOS 7

Sources :
https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-mod_deflate-on-centos-7

http://www.linux-faqs.info/apache/optimize-website-speed-with-mod-expire-and-mod-deflate

http://tecadmin.net/how-to-enable-gzip-compression-on-apache/

http://idroot.net/tutorials/how-to-enable-gzip-compression-on-apache/

http://seositecheckup.com/articles/how-using-gzip-compression-helps-your-sites-seo