Web Vitals is an initiative by Google to provide unified guidance for quality signals that are essential to delivering a great user experience on the web or mobile web.
Google has provided a number of tools over the years to measure and report on performance. Some developers are experts at using these tools, while others have found the abundance of both tools and metrics challenging to keep up with.
The Web Vitals initiative aims to simplify the landscape, and help sites focus on the metrics that matter most, the Core Web Vitals.
Core Web Vitals are the subset of Web Vitals that apply to all web pages, should be measured by all site owners, and will be surfaced across all Google tools. Each of the Core Web Vitals represents a distinct facet of the user experience, is measurable in the field, and reflects the real-world experience of a critical user-centric outcome.
The metrics that make up Core Web Vitals will evolve over time. The current set for 2020 focuses on three aspects of the user experience loading, interactivity, and visual stability and includes the following metrics (and their respective thresholds):
Core Web Vitals is a signal for Search Engine Optimization (SEO) and Google will combine with their existing signals.
You can your site's Core Web Vitals data in the Experience menu and Core Web Vitals submenu on your Google Search Console account.
Other Web Vitals are Mobile Friendly, Safe-browsing (not having malware on your website), HTTPS and Non Intrusive Interstitials ads.
You can learn more about web vitals on https://web.dev/vitals