Unlike the rest of the library, the Logger is not an Interface control that is designed to be used in production applications. The Logger control is just for you, the developer, to assist you primarily in the design phase of your site or application, but also in maintenance or upgrade phases as and when required.
Like any of the controls provided by the library, Logger is both easy to implement and easy to use. It provides a mechanism for both the writing and reading of log messages generated by your application at key moments during its use.
JavaScript provides no console support natively. It is usually left to the browser or interpreting environment to manage and report runtime errors, and as I'm sure you're aware, browsers don't always provide as robust or intelligible results that we as developers would like!