html have a several new tags for example video,audio ..etc

Question

see more here:
https://www.w3schools.com/html/html5_new_elements.asp

Answer 1

Interesting :)
https://www.sololearn.com/learn/HTML/2211/?ref=app

Answer 2

The List of Content Models
In HTML, elements typically belonged in either the block level or inline content model. HTML5 introduces seven main content models.
- Metadata
- Embedded
- Interactive
- Heading
- Phrasing
- Flow
- Sectioning
......................
Totally 7 content models
Metadata: Content that sets up the presentation or behavior of the rest of the content. These elements are found in the head of the document.
Elements: <base>, <link>, <meta>, <noscript>, <script>, <style>, <title>
Embedded: Content that imports other resources into the document.
Elements: <audio>, <video>, <canvas>, <iframe>, <img>, <math>, <object>, <svg>
Interactive: Content specifically intended for user interaction.
Elements: <a>, <audio>, <video>, <button>, <details>, <embed>, <iframe>, <img>, <input>, <label>, <object>, <select>, <textarea>
Heading: Defines a section header.
Elements: <h1>, <h2>, <h3>, <h4>, <h5>, <h6>, <hgroup>
Phrasing: This model has a number of inline level elements in common with HTML4.
Elements: <img>, <span>, <strong>, <label>, <br />, <small>, <sub>, and more.