What are the effects of Google core update?

What are the effects of Google core update?

Director of Product Search at Google Elizabeth Tucker stated that the new core update will “collectively reduce low-quality, unoriginal content in search results by 40%.”  This update made changes simultaneously to multiple core systems and people from Google warned that there will be fluctuations in rankings as each of these systems are updated and begin to reinforce each other.

Many of the things mentioned earlier with the previous updates were baked into this one large update, including reviews updates, spam updates, and curbing unhelpful content, aggressive ads, poor user experience, and content created for search instead of users.  The update ended up reducing low-quality, unoriginal content in the search results by 45 percent, more than the expected 40 percent, which led to massive volatility.  Some websites initially surged and then dropped while other websites experienced the opposite.  Many were still reporting volatility in their rankings and traffic as late as May.