I got the Wrox.Beginning.JavaScript.3rd.Edition and wanted to start learning it from scratch, then my boss came along and said that why bother, learn jQuery. Can I understand jQ
So what's your question? JQuery is a framework built on the top of a language JavaScript. To use JQuery confidently, you should get familiar with JavaScript. JQuery contains a bunch of useful patterns and utils that mask the incompatibilities of the browsers. Using a JavaScript framework make sense as it allows you to focus on your problem instead of the problem of the JavaScript implementations of the browsers.
For further details on JavaScript frameworks, see SO question »Which Javascript framework (jQuery vs Dojo vs … )?«. For learning JavaScript, learn the good parts.