The introduction of MUM represents the next major paradigm shift for Google search after Hummingbird, Rankbrain and BERT. While the previous innovations based on machine learning are based on several trained models for different tasks, the goal at MUM is to use only one model for all tasks related to indexing, information retrieval and ranking. That streamlining of machine learning models has a host of benefits for search performance, but before you can fully appreciate what a major change MUM represents, you must first understand what we’re dealing with here. read in details: https://searchengineland.com/google-mum-update-seo-future-383551