I stumbled upon relevance search while revising for the exam MB-200: Microsoft Dynamics 365 Customer Engagement Core. After reading a brief overview my curiosity was peaked as to how it all works and just how 'relevant' the searching might or could possibly be. It turns out that it's pretty impressive at both a user experience and technical level, but only your system configurations are made knowledgeably.
Full article can be found in its original posting here -> https://www.linkedin.com/pulse/relevance-search-d365-good-so-things-consider-amey-holden/