DOM stands for ‘Document Object Model’. In simple terms, it is a structured representation of the HTML elements that are present in a webpage or web app. DOM represents the entire UI of your application. The DOM is represented as a tree data structure. It contains a node for each UI element present in the web document. It is very useful as it allows web developers to modify content through JavaScript, also it being in structured format helps a lot as we can choose specific targets and all the code becomes much easier to work with.
The HTML DOM provides an interface (API) to traverse and modify the nodes. It contains methods like getElementById or removeChild. We usually use JavaScript language to work with the DOM, because… Well, nobody knows why :).
So, whenever we want to dynamically change the content of the web page, we modify the DOM:
var item = document.getElementById("myLI");
item.parentNode.removeChild(item);