It presents the amount or percentage of the visitants who visit the site and leave at the same time without checking other sites on the same page. If the success rate of your website is depended on the bounce rate then you need to mitigate it a bit. Suppose, your front page is the gateway to other sites, and viewers are just viewing your front page instead of other websites then, a high bounce rate is not at all good for your site. But for a single page site like a blog or something, high bounce rate is not that alarming. Try to make your content worth reading and also, include useful details on your website, to engage the visitants to remain for a longer time on your website rather than to bounce back.