How does Keats define a thing of beauty?

 According to Keats, the thing of beauty is the source of endless joy. It never fades away, rather its charms increases with the passage of time. The shapes of beautiful things keep us bound to out nature as well as earth. A thing of beauty has the capability of encharming even the most dampen spirit. Therefore the things of beauty, which have been bestowed upon us by God, refresh and revitalize our lives.