A bounce is a session with a single page view on your website. In Google Analytics, a bounce is a session in which only one request to the Google Analytics server was activated (for example, if a user opened one page of the site and left without activating any other requests).
The bounce rate is calculated by dividing the number of sessions with a single page view by the total number of sessions, i.e. as a proportion of the total number of sessions. The duration of a session with a single pageview is always considered to be 0 seconds, because nothing else happens after the first request and the system cannot calculate the actual session duration.
