This is one of the top SEO questions this year that you should master. Dwell time is how long a user stays on the page of a website after s/he finds it on the Google SERP and goes back to the search results. If the dwell time is less, it means the user did not find the page useful. It is also relative to the SEO content you create.
For instance, a user looking for a quick short answer will not take much time on the page, provided s/he gets the answer without having to leap through distracting video ads that roll automatically as you scroll down content. But if the content is long with an embedded video, the user will obviously spend a considerable amount of satisfactory time and Google will deem it as useful.
Although this is not a direct ranking factor in Google, it is part of the search engine’s machine learning algorithm. It is also different from the bounce rate metric which calculates a single session against all the pages of a website.
