Penguin is the name of an algorithm created by Google.
The most recent update, Penguin 4.0, penalize, in real time, sites with links that comes from low-quality sites, better known as links for hire.
Additionally, Penguin 4.0, reward websites with better-quality inbound link profiles.
This real-time feature allows sites that warranted a penalty for bad links, and then removed, to be forgiven and avoid months for the next refresh to see the effects.
Additionally, Google confirmed that Penguin 4.0, is a filter to capture websites deemed spammy and it is working in all languages.
The last update was made in 2014, Penguin 3.0, affected about 1% of the searches in the US, but now with the multilingual adjustment will be affecting many more sites worldwide.
In Digisolution we advise all our customers to avoid the temptation and build a real link network, which will be a real win-win strategy for their sites and the origin sites.