78. What is the DOM? (Document Object Model)
The Document Object Model (DOM) is an interface that treats an HTML or XML document as a tree structure, where each node in the tree represents a part of the document (elements, attributes, text, etc.).
JavaScript interacts with the web page almost entirely through the DOM.
The DOM Tree
If you have this HTML:
html
Hello
Text
The DOM represents it as a hierarchy:
window(Global object)document(The entry point)<html><head><body><h1>(Element node)- 'Hello' (Text node)
<p>(Element node)
Why is the DOM necessary?
It provides a standardized way for JavaScript to:
- Find elements on the page.
- Change the content (text or attributes) of elements.
- Add or Remove elements dynamically.
- Respond to user actions (like clicks).