What Is CLS? How (and Why) to Measure It

Cumulative Layout Shift measures the total amount of layout shifts that occur on a web page as it loads and is interacted with. Google measures CLS in order to judge the overall page experience alongside the other two core web vitals, First Input Delay (FID) and Largest Contentful Paint (LCP).

from Semrush blog https://www.semrush.com/blog/what-is-cls

source https://socialmediamarketingconsultantseo.blogspot.com/2023/02/what-is-cls-how-and-why-to-measure-it.html