Google ranking systems
Google's documented list of the systems that generate rankings, distinguished from one-off 'updates' to those systems, and…
GoogleSystemConfirmedHigh impact
Hummingbird
Rewrite of Google's core query-processing engine to interpret the meaning of a whole query rather than matching individual keywords.
What changed
Hummingbird replaced the ranking engine's query-understanding layer so that conversational and long questions could be matched to documents on meaning rather than literal keywords. Google announced it at a press event on 26 September 2013 and said it had already been live for about a month, so no precise launch date exists. It underpinned the Knowledge Graph era and voice search, and it is the platform on which later language systems such as RankBrain and BERT were built.
Timing
Rollout began 26 September 2013. No completion date was announced. Rankings typically remain unstable for the whole rollout window, so measurements taken inside it are not a reliable read on the outcome.
What it affected
Related terminology
Hummingbird
Google's 2013 rewrite of its core ranking infrastructure, shifting emphasis from individual keywords toward the meaning of whole…
Semantic search
Retrieval based on the meaning of a query and documents rather than literal keyword matching, using entities, context and…