The bounce rate. This is the number of visitors who leave your website within ten seconds. At least, this is often claimed, but that is no longer true. Google Analytics actually cannot know how long someone stays on the bounce page.
Google Analytics measures time on a page using time-outs. Suppose you visit a website at 12:00. Then, at 12:08, Google Analytics detects that you land on another page. Only then is it clear how long you spent on the first page. In this case, that is 8 minutes. If you were to visit only the first page, Google Analytics would not know how long you were there.
That is strange. Suppose you find the information you are looking for immediately on the homepage; then you leave the website again, and Google Analytics doesn't know how long you were there.
A high bounce rate is therefore not always a bad thing. Suppose someone lands on a specific page of your website via Google. The visitor immediately finds the information they were looking for and closes the browser. Google Analytics now views this as a bounce, even though the visitor found what they were looking for.
Conclusion: nothing needs to be done immediately about a webpage with a high bounce rate. A bounce can therefore mean that someone visited only one page, but spent ten minutes viewing and reading it.