Cumulative layout shifts are one of many indicators we use to measure site speed, which can affect ranking in our search results. This metric reflects changes made on-page such as load time or scrolling behavior after consecutive visits over extended periods of time (days). The more cumulative layouts shift occur during this period, the higher likelihood there is an issue with page loading times or design efficiency causing poor user experience. CLS becomes relevant from 2021 onwards when it comes into effect as a ranking factor but until then you need to make sure your pages meet all expectations by reducing average load times below 3 seconds.