The DOM (Document Object Model) plays a crucial role in web page rendering as it represents the structure of an HTML document in a tree-like format. When a browser loads a web page, it parses the HTML code and constructs the DOM, which maps out all elements, attributes, and content of the page in a hierarchical model. Each node in the DOM corresponds to an element in the HTML structure, allowing developers to dynamically interact with and manipulate the content using JavaScript.

Rendering starts after the DOM is built, combining it with CSS to create the visual presentation of the web page. Any changes made to the DOM using JavaScript (such as adding or modifying elements) result in the browser updating or re-rendering parts of the page. The efficiency of this process directly affects the performance and responsiveness of a website. As a result, optimizing DOM manipulation is key to building fast and interactive websites.

Mastering DOM manipulation and understanding its impact on rendering are essential skills in front-end web development. For those looking to learn these concepts in-depth and build a strong foundation in front-end technologies, a website development course is an excellent place to start.