Google has defined a set of metrics that website owners should focus on for optimization.
By defining these Core Web Vitals, Google aims to provide unified guidance for quality signals that they say are “essential to delivering a great user experience on the web” and that “Optimizing for quality of user experience is key to the long-term success of any site on the web.”
Google emphasizes the importance of Core Web Vitals over other metrics as they’re critical to all web experiences. Users’ expectations for web experiences can vary according to site and context, but many remain consistent regardless of where they are on the web.
Core Web Vitals are the user experience needs that all websites should be striving to meet. Specifically, Google identifies the core user experience needs as: loading, interactivity, and visual stability.