Document Object Model

The DOM (Document Object Model) is a programming interface for HTML, XML and SVG documents. It provides a structured representation of the document (a tree) and it defines a way that the structure can be accessed from programs so that they can change the document structure, style and content. The DOM provides a representation of the document as a structured group of nodes and objects that have properties and methods. Nodes can also have event handlers attached to them, and once that event is triggered the event handlers get executed. Essentially, it connects web pages to scripts or programming languages.

You can check the example of the DOM structure on the following screenshot.

Though often accessed using JavaScript, the DOM itself is not a part of the JavaScript language, and it can be accessed by other languages, though this is much less common.