Prior to 2011, it was easy to game search engines and gain undue ranking and visibility advantage. A lot of businesses did benefit which impacted the kind of quality search results major search engines like Google hoped to give to end users.
This is when Google decided to do something concrete to restrict the undue freedom enjoyed by marketers. Between 2011 and 2016, it made drastic changes to its algorithms in the form of regular updates. Panda and Penguin were such updates with the purpose to curb malicious practices employed to gain ranking advantages.
Panda updates were a series of algorithm changes aimed at identifying and penalizing low-quality content and rewarding good-quality ones. On the other hand, Penguin updates were a series of algorithm changes that aimed at targeting and penalizing unfair SEO tactics or methods employed by marketers or websites to rank better.
With Panda updates, it’s now not possible to gain in search engines without having original, informative, in-depth and value-addition content. Similarly, sites engaging in buying links or sites with too many irrelevant links can no longer gain any advantage.