The DOM

A browsers in-memory representation of the HTML document.

What is the DOM?

The DOM is the Document Object Model. It is a representation of the HTML document that has been loaded into the browsers memory.

The DOM lives in the memory of the browser and can be manipuated by JavaScript. You can access elements of the DOM as follows.

document.getElementById('firstNameBox');

Changes that are made to the DOM do NOT affect the original HTML from which the page was loaded.

Level: Apprentice · More JavaScript terms at this level

Updated October 16, 2026