Google Page Speed Insights
Page Speed Insights (PSI) provides information on the technical performance of a page on mobile and desktop devices subsequently. It provides a scoring against adherence to Google’s page speed best practises (determined by running Google Lighthouse) with suggestions on how it can be improved.
PSI provides both field and lab data for a web page. Lab data helps with debugging real time performance issues whereas field data is useful for capturing the true user experience.
Core Web Vitals
These are a collective set of signals essential to good web experience from a user’s perspective. User experience is becoming an increasingly weighted factor when it comes to SEO performance, Google wants to provide users with the best possible experience therefore rewards websites that pass the core web vitals assessment, and do not rank as favourable on sites that do not.
PSI presents the core web vital and additional metrics so that developers can understand the range of values and performance for each category. There is usually a time saving associated to each recommended opportunity or diagnostic