'DOM (Document Object Model)' is an interface used in programming for web documents. It depicts the page in a manner that allows programs to alter its structure, style, and content. The DOM treats the document as a series of nodes and objects, enabling interaction with the page through programming languages.

A web page is essentially a document, viewable either in a browser window or as HTML code. The DOM offers an object-oriented representation of this web page, which can be altered using scripting languages like JavaScript.

Providing a structured representation of the document as nodes and objects, the DOM mirrors how the browser perceives the document. When a web page is loaded, the browser generates a Document Object Model of that page, an object-oriented depiction of the HTML document. This model allows for the addition, alteration, and deletion of elements within the document.

Beyond HTML, the DOM is equally applicable to XML documents. It stands as a vital element in web development, empowering scripting languages to dynamically update a document's content, structure, and style during viewing.

Summarizing, the DOM is fundamental in web development, underpinning the creation of dynamic and interactive web applications. It facilitates developers in crafting scripts that can dynamically modify the content, structure, and style of documents as they are viewed, significantly enhancing user interaction with web pages.