The Document Object Model (DOM) connects web pages to scripts or programming languages by representing the structure of a document—such as the HTML representing a web page—in memory.
DOM Level 1 provided a complete model for an entire HTML or XML document, including the means to change any portion of the document. DOM Level 2 was published in late 2000. It introduced the getElementById function as well as an event model and support for XML namespaces and CSS.
The DOM tells a browser how to render the web page’s content, and allows web developers to edit the DOM via source code. In this article below, we’ll look at what the DOM is, what it looks like, how it’s used, and why you should care.