What is the function of the Document Object Model (DOM)?

The Document Object Model (DOM) serves the crucial function of representing and interacting with the structure of a web document. It is a programming interface that allows developers to manipulate the content, structure, and style of a document dynamically. When a web page is loaded, the browser creates a DOM of the page that represents all elements, such as elements of HTML or XML, as a tree of objects. This enables scripting languages like JavaScript to modify the document's content by adding, removing, or changing elements and their attributes, leading to a dynamic and interactive user experience.

This capability is fundamental for developing modern web applications, as it allows for real-time updates and manipulation of the content presented to users without requiring a page reload. The other options do not pertain to the core functionality of the DOM: creating CSS stylesheets pertains to styling, defining HTTP protocols relates to data transfer on the web, and managing database connections involves backend operations rather than document structure.