jQuery basically breaks down into two operations: picking things, and doing something with those things. Picking things is done via a CSS / XPath strign describing the DOM nodes you want to do. This returns an array of DOM elements (wrapped nicely in a jQuery object) that get passed into each of jQuery’s ‘do it’ functions. It becomes trivial to change css on all items, change the innerHTML, append DOM elements, even do AJAX and visual effects. What’s best: this whole process usually takes about 20 characters — very small, very clean, very nice.
The slides from the content can be found here. We generated all the code we saw on the fly inside FireBug. Enjoy!