JQUERY on the other hand is very simple to write and is cross browser specific meaning in almost all cases functions will work across all browsers. This greatly simplifies development time. That said error reporting is no better but with the reduced complexity in development it's easier to find where the problem is especially if you take your time testing as you develop. So now you understand what is JQUERY.
Finally JQUERY is 100% free and its relativity simple to learn. Just start with some basic functions and build on it from there. In short it's all about linking events to the DOM - Document Object Model and the performing functions when these Events are triggered - EG: when a user Clicks on a Button the Event is captured and this causes a new DIV to appear with extra options etc.