What is a Google Core Update?
A core update is a significant change in Google’s algorithm that improves the quality and relevance of search results by shuffling the rankings of indexed pages.
More About Google Core Updates
Each core update tweaks Google’s ranking formula and can affect many websites. Pages that rank high for specific keywords may rank lower after a core update.
Core algorithm updates are typically made every few months. Google usually announces upcoming updates in advance and describes their goals.
Furthermore, core updates may take several weeks to roll out. On the other hand, minor updates are sometimes done daily.