Bounce rate is a visitor engagement metric used to calculate how many visitors exit a website after viewing just one page. They don’t perform any action (like clicking a link or navigating to any other page). It’s a key web analytic metric that indicates the effectiveness of a page and user engagement.

If the bounce rate is high, it may indicate a problem with slow loading speed, the irrelevance of content, or an unsatisfactory user experience.  The bounce rate for Google Analytics is calculated by the single-page visits divided by the total number of visits. 

A lower bounce rate means websites have fast page loading speed, better relevance of content, and improved navigation experience. Having a high bounce rate means that your website needs to be optimized, and your content should be relevant.