The DOM is a structure that holds the content of a document and all of its related files, images, and other elements. It also contains a set of rules to describe how these elements are displayed on the screen, and how they connect with each other. This makes it possible for a web browser to display a webpage in any desired format.
It is also important to understand the execution order of a script. Scripts with the async attribute will be executed as soon as they are downloaded, and scripts with the defer attribute will be loaded first, and then executed in the order that they were placed in the