Algorithms & Quality
19 terms in this domain · show all 220
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Helpful Content System (HCU)
The Helpful Content System is Google's framework for distinguishing people-first content from search-engine-first content. Originally launched in August 2022 as a separate sitewide classifier, it was folded into the core ranking signals during the March 2024 core update.
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Hummingbird
Hummingbird is the algorithm overhaul Google announced in September 2013 — the largest rewrite since Caffeine in 2010. It shifted ranking from keyword-by-keyword matching toward parsing the full query for intent and meaning. Hummingbird is the foundation later systems like RankBrain, BERT, and MUM extended.
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Page experience update
The page experience update rolled out to mobile in June 2021 and to desktop in February 2022. It bundled Core Web Vitals (LCP, FID/INP, CLS) with HTTPS, no intrusive interstitials, and mobile-friendliness into a unified ranking signal. Now described as part of Google's broader page experience ranking systems rather than a discrete update.
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PageRank
PageRank is the original Google ranking algorithm, patented by Larry Page and Sergey Brin at Stanford in 1998. It scores pages by the quantity and quality of inbound links. The public Toolbar PageRank score was deprecated in 2016, but Google has confirmed the underlying signal is still operational.
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Panda algorithm
Panda was the algorithmic update Google launched on February 23, 2011, to target thin, duplicate, and low-quality content — particularly content farms that had dominated SERPs in 2010. Periodic refreshes ran for five years, then Panda was folded into Google's core algorithm in January 2016.
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Parasite SEO
Parasite SEO is the practice of publishing content on a high-authority host domain to rank queries the publisher's own site couldn't reach. Common hosts: major news sites, LinkedIn articles, Medium, university subdomains. Google targeted the publisher-host variant directly with the site reputation abuse policy in May 2024.
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Penguin algorithm
Penguin was Google's algorithmic update launched on April 24, 2012, to combat manipulative backlink patterns — link schemes, exact-match anchor abuse, paid links, low-quality directories. Penguin 4.0 (September 2016) made it real-time and granular, devaluing bad links rather than penalizing whole sites.
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RankBrain
RankBrain is Google's first major machine learning system applied to search ranking, confirmed in October 2015. It helps interpret novel, ambiguous, or never-before-seen queries by mapping them to similar known queries. Still operational today as one of many signals in the ranking system.
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Reviews update
The reviews update — now called the Reviews System and folded into the core ranking system in November 2023 — targets thin or aggregator-style review content. Google rewards first-hand evaluation, side-by-side comparison, original photography or video, and clear evidence the reviewer used the product.
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Site reputation abuse
Site reputation abuse is publishing third-party content on a high-authority host site primarily to manipulate rankings, when that content has little oversight from the host and is unrelated to its main purpose. Codified as a Google spam policy in May 2024. Targets coupon sections, sponsored deal hubs, and rented subdirectories.
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Spam update
A spam update is a targeted enforcement run against Google's published spam policies — cloaking, sneaky redirects, scaled content abuse, link schemes, doorways. Distinct from a core update, which reweights quality signals broadly. Recovery requires removing the offending pattern, not waiting it out.