1. DOM Document Object Model: Manipulate page elements (tags)
- The html file is regarded as a document, and the document is regarded as an object
- XML is also a kind of document, the label is customized, the system does not have its own label, and it is inclined to store data
2. DOM tree: a tree structure diagram composed of a document and all elements (tags) in the document, called a tree diagram, also called a DOM tree
- Element (element): Each label in the page is an element, and each element is an object
- Document: A page is a document
- Node (node): All content on the page is a node, including labels, attributes, text
3. DOM operation case: