The Document Object Model (DOM) is a representation of a web page as objects and nodes. Programming languages use the DOM to interact with and manipulate the page.
The World Wide Web Consortium (W3C) is responsible for developing the DOM specifications.
Browsers implement the DOM via the HTML DOM API. This API allows access and/or changes to HTML elements, CSS stylesheets, browser tabs/windows, and browser history.
The DOM represents a web page as nodes and objects so programming languages can manipulate the page. The W3C develops the specifications for the DOM. Browsers implement the DOM using the HTML DOM API, which allows access and manipulation to a page's HTML and CSS code. Browser tabs and history can also be accessed.