Bounce rate is the percentage of visitors who view a page and leave the page without viewing other pages. The higher the bounce rate, the poorer the performance of the page in holding the interest of the visitor.
Creative and relevant content on the landing page of any website will likely make visitors continue exploring website. Therefore a good landing page is absolutely essential in retaining first time visitors.
Bounce rate is has an inverse relationship with effectiveness of a page. A low bounce rate shows that the page is effective.
A few pointers on how to reduce the bounce rate are given on this link about landing pages.