Directory submission is the process of adding your website to a relative web directory for free. These sites are best for getting the higher traffic and search engine visibility. Submission of websites in do-follow directory sites helps in boosting your websites and improves your site ranking in search engine results.
These sites are with PR (pr 9, pr 8, pr 7 , pr 6, pr 5, pr 4) through which you will get quality backlinks. While submitting your websites to these directories, you should be careful about the Google Panda, Hummingbird and Penguin algorithm. If you submit your website in large volume then the algorithm can decrease your site appearance. Listing a website in high-rank do follow websites will help to improve your site rank and online presence.