Core Web Vitals Assessment
When PageSpeed insights has analyzed your site the results will load on the page. This starts with an assessment of the Core Web Vitals, a collection of metrics that Google consider the most important to real world users. These are the Largest Contentful Paint (LCP), the First input Delay (FID), and the Cumulative Layout Shift (CLS).
Under these other notable metrics are also reported such as First Contentful Paint (FCP), Interaction To Next Paint (INP), and Time To First Byte (TTFB). You can see these results for both Mobile and Desktop. You will notice that the report defaults to the Mobile Results, in line with Google’s Mobile First Indexing. See the Desktop results by clicking on the Desktop link.
There Is also an Expand View link to get more detail for these metrics. PSI classifies the quality of user experiences into three buckets: Good, Needs Improvement, or Poor. Your users experiences are distributed aloing the line, which is also marked with the 75th percentile for that metric.
Just to clarify how to read these figures. If we look at the image below, we can see that 76% of page loads got a good result with the Largest Contentful Paint, a full 99% for the First Input Delay, and 89% for the Cumulative Layout Shift. To pass the Core Web Vitals Assessment, you need the percentage of page loads in the Good section to be at or above the 75th percentile.
To read more about how Google defines the Core Web Vital metrics threshholds, see the following page. You can also read more about this in the PageSpeed Insight Docs.