RankBrain is a machine learning artificial intelligence system that was launched by Google on 26 October 2015 to perform better search on queries that users key in on Google. It is being applied to and is being used along with the Google’s current search engine algorithms in order to provide more relevant results for the various user queries.

Now what exactly do the terms, ‘machine learning’ and ‘artificial intelligence’ mean?

Machine learning is where a computer itself learns how to perform a particular task, rather than being taught by the humans or by following a specific detailed programming.

The artificial intelligence, or AI for short means that the computer is as smart a human in terms of acquiring knowledge. It learns from being taught as well as from the building new connections over what it already knows.

A good search engine does not endeavor to return all those pages that match the input query most. Rather, a good search engine is one that tries to answer the underlying question of the input query. This is how the Google along with the other search engines work. Here Google uses a complex algorithm to sort through the billions of pages it knows about, and delivers the ones that are most relevant to the particular queries.

RankBrain is part of Google’s overall search “algorithm,” which is called Hummingbird. Initially the overall algorithm didn’t have a formal name but in mid of 2013, Google revamped that algorithm and gave it the name, ‘Hummingbird’.

How does RankBrain work?

RankBrain uses artificial intelligence to embed huge amount of language into mathematical entities called the vectors. If RankBrain sees a word or a phrase that it isn’t aware of, the machine makes guesses of the various words or phrases that might have a similar meaning to it. It then filters the results correspondingly and makes it more effective in handling the ‘never before seen search queries’.

There are more than 200 different ranking factors, which altogether forms the ranking algorithm of Google. And Google being pretty secretive it is impossible to figure out the precise mechanics of its ranking algorithm. The general idea is that the RankBrain interprets the user searches to search pages that may not have the precise words used as an input in the search query. While offline, the RankBrain is provided with the batches of past searches and thus it learns by matching the various search results. Once RankBrain's results get verified by the Google's team, the system is revised and it goes live all over again.

RankBrain can in fact be regarded as a new ranking signal. Signals are elements the Google uses to determine ways to rank Web pages. Talking of ranking signals, this has been proven to be the third most important in determining the ultimate rank of a given page.

It would be sensible to say it affects Search Engine Optimization (SEO) as the SEO. Defining the keywords and optimization of content have always remained the foundation phase in the SEO process. Hence RankBrain affects the performance of SEO campaigns as it strives to learn, change and improvise the searches as well as the rankings. Precisely, we can say that the SEO campaigns will be more adaptable to changes in rankings landscape.