Google launched another algorithm update in the name of Penguin in April 2012 for the field of SEO. It came out as another blow to the websites ranking. This update penalized a website and decreased its rankings on breaching Google’s webmaster guidelines as per the search engine norms.
Penguin Role lowers the search engine ranks of all those websites practicing black-hat SEO techniques such as duplicate content, too much keyword stuffing in content and cloaking (content presented to the search engine spider is different from that presented to the user's browser), meaningless content, over search optimization, excessive link building. Its main focus is to penalize those unnatural links that cause changes in the search results deliberately.
Penguin updates happened 4 times with the latest one announced officially from google on Friday 23, 2016 since its launch.
The Penguin algorithm generally affects one part of the website on a page and keyword level. It does not damage the entire site unless too much keyword usage spamming has been done.
Avoid Penguin penalty by;
Removing all the bad links, Google offered a disavow links tool that removes unnatural links from your website
Optimizing content sent to search engines as per the keywords mentioned for the relevant pages
Have no broken links and maintain the quality of content, which means no plagiarism or duplicated work
Have no promotion of malicious content on your site
Never using black-hat techniques (keyword stuffing and cloaking)
Divert links and keep using different anchor texts
Guest posting is nice, but note that Google takes these post as back-links and can consider it as a negative aspect on your site.
Merge site with as many social sites as possible, specifically Google Plus to reach out to the other parts of the world