CSS was built on the idea of separating display from structure in an HTML document. jQuery was built on similar principals, with the idea of separating behavior from structure. If you are familiar with jQuery, then you probably know about selecting elements by class or ID. jQuery contains a wealth of other ways to select elements when using just classes and Ids won’t cut it. Using these selectors are great when you are working with many HTML elements, and allows you to do very impressive things with very small amounts of code.

The terms ‘children’ and ’sibling’ elements are a common term in the computer world. When talking about HTML, child elements are elements that are inside of another element, which is called their parent element. Elements that ...