What is the DOM?
The DOM, Document Object Model, is an interface used for web documents that allows programming languages to interact with, and change the structure and content of a page. It is also a collection of APIs, or pre-built code, that allows users to easily code their own site without needing to write every line of code associated with a task.
DOM Specifications
The specifications created for the DOM and it's capabilities is maintained by the W3C, where they have highly detailed documentation regarding any and all specifications the DOM must meet. The shortened explanation of the specifications listed is to ensure that the DOM is a platform and language neutral interface, that allows other programs and scrips to access and update the content, structure, and style of documents. It is important that the DOM remains platform and language neutral, as it allows users of any device, as well as the use of any coding language, to interact and use a site to the same capacity as any other user.
DOM Implementation in Browsers
The DOM is often shown in a tree / grove like diagram, where this tree describes the content of a page. It starts at the HTML element, and builds on from there into other sections, like the 'head', 'body', 'footer', etc. Each of those are then built upon with any elements inside of those, like the 'head' section having 'meta', 'title', 'link', etc. The tree structure of the DOM is designed to represent how each element is related to one another, and the hierarchy that exists between the elements.
Conclusion
In conclusion, the DOM is a model / interface that allows other languages to interact and modify elements on the page. The DOM also has a series of specifications it follows to ensure that it is platform and language neutral, to ensure equal accessibility to all users of all devices. Lastly, the creation of the DOM is represented in a tree-like formation, where the hierarchy and relationships of elements to on another are shown.