Bounce rate is a Web analytics term that refers to the percentage of visitors who leave a website instead of viewing more pages. These visitors land on a particular page, usually through a search engine, but then leave the site rather than going in deeper. Bounce rate may also be referred to as exit rate.
Techopedia explains Bounce Rate
A high bounce rate suggests that the content on the page is not relevant to what visitors were looking for. That said, it may also mean that the page answered their specific query perfectly and they felt no need to explore further. There is no standard bounce rate that is considered good or bad, so bounce rate is only meaningful when considered alongside other analytical data.