What is jQuery Really?

jQuery can drastically simplify and alleviate many headaches when working with HTML, CSS, and JavaScript. Taking a little time to understand how a tool works — the mechanism that drives it — is often the difference between having access to a tool and having command over it.

To better understand what jQuery is doing under the hood, it is helpful to understand a little bit about the DOM. The DOM (Document Object Model) is a programming interface, built by browsers, which represents the structure of a web document in memory. It is created when a webpage is loaded, representing the document with a tree-like structure. The DOM can be thought of like a bridge or a hub, allowing a webpage's content, styling, and interactivity to be accessed and manipulated dynamically.

A look under the hood — engine components exposed, illustrating the mechanism beneath the surface.

The DOM Problem jQuery Solves

The DOM exposes a set of built-in browser APIs for accessing and manipulating elements.…