After a two year wait, Google’s Penguin algorithm has received an update on the 23rd of September 2016. Penguin is one of the 200 or so signals and clues that Google takes into account when returning search results, and it is a spam detection algorithm that is designed to capture sites that get past normal spam filters.
Penguin 4.0 will also be real time. In the past, almost all Google algorithms would take into account any changes made to a website instantaneously. This was not the case for Penguin, which needed to be refreshed manually. With this new update, pages will be re-indexed and re-crawled in real time, which means that changes will be taken into account automatically, and that future refreshes of the algorithm will be unannounced.
Penguin has also become more granular. Previously, the algorithm would derank an entire website, but with this update, Penguin affects ranking based on specific spam signals. What this means, is up to interpretation. When asked whether this means that Penguin would affect only specific pages, Google stated that that is not the case, and that it affects finer granularity rather than sites.
This update is good news for any webmaster who has had problems with the manual refresh times of the previous editions. A real-time Penguin means that websites can quickly bounce back from a deranking if they start implementing white hat SEO techniques. As for the granularity aspect of this update, your guess is as good as ours. Whether it refers to the fact that Penguin now takes many more spam signals into account, or if deranking only affects a single part of the website remains to be seen.