The Document Object Model, or DOM, is a programming interface that allows scripts to access and manipulate the structure of a web document. It represents the document as a tree of objects, where each element, attribute, and piece of text is a node. This makes it easier for developers to change the content, structure, and style of a webpage dynamically. Using the DOM, developers can create interactive web applications by responding to user actions, such as clicks or keyboard input. The DOM is essential for modern web development, as it enables the use of languages like JavaScript to enhance user experience and functionality on websites.