BERT is the biggest change Google has released since RankBrain and it is expected to impact 1 in 10 of all search queries.

Google is introducing new algorithm which will impact on 1 in every 10 queries in terms of changing the results that rank for those queries. This is said to be the biggest change since RankBrain about 5 years back.
What is BERT? BERT stands for Bidirectional Encoder Representations from Transformers and unless you work in Google and not looking for changing jobs in SEO, you don’t need to remember the full form. BERT is Google’s network based technique to process natural languages.

BERT started rolling out this week and will be fully live shortly. It is rolling out for English language first, followed by other languages in the future. This will also impact featured snippets. Google is planning to launch BERT globally, in all languages, on featured snippets.
To explain in a simple way. BERT can help computers understand language a bit more like humans do. Google claims that BERT will help machines to better understand the nuances and context of words in searches and better match those queries with more relevant results. It is also used for featured snippets, as described above.