Website Bounces or Bounce Rate is a measure of stickiness, and is a good starting point when analyzing the fit of your content to the users you are attracting. In other words, it's those two fundamental elements, the right audience, and the right content, that will impact how many single page visits, or bounces, you get.
Bounces will happen for a number of reasons, such as clicking "back", closing the browser window or tab, clicking on a link to a new website, typing in a new URL, or reaching a session timeout.
Keep in mind that if you have a single page website or a highly compelling landing page, users might find everything they need, and still be considered a bounce. For this reason, you should always look at related metrics, such as Average Time on Site to get a better understanding of the quality of your traffic and the performance of your content.