SEO
RankBrain
Quick definition
RankBrain is a machine-learning algorithm Google uses to better understand the meaning behind queries — especially novel or ambiguous ones.
Launched in 2015, RankBrain was the first major ML system in Google Search. It interprets query intent, synonyms, and entity relationships.
Why RankBrain matters
RankBrain matters because it shifted SEO from keyword matching toward intent matching. Content needs to satisfy the topic, not just contain exact phrases.
How RankBrain works in practice
Optimize for RankBrain by writing comprehensively on topics, using semantically related terms, and aligning content to the actual SERP intent rather than keyword density.