Structure and semantics of HTML5 (1): Preface_html5 tutorial skills

Hypertext Markup Language (HTML) 5 introduces new elements to HTML for the first time. New structural elements include aside, figure, and section. New inline elements include time, meter, and progress. New inline elements are video and audio. New interactive elements are details, datagrid and command.
Development of Hypertext Markup Language (HTML) stopped with HTML 4 in 1999. The World Wide Web Consortium (W3C) has turned its focus to changing the underlying syntax of HTML from Standard Generalized Markup Language (SGML) to Extensible Markup Language (XML), as well as new markup languages ​​such as Scalable Vector Graphics (SVG), XForms and MathML. Browser manufacturers are focusing on browser features such as tabs and rich site summary (RSS) readers. Web designers are beginning to learn to use asynchronous JavaScript XML (Ajax) to build their applications within existing frameworks using Cascading Style Sheets (CSS) and the JavaScript™ language. But for the next eight years, nothing changed in HTML itself.
Recently, it has been revived. Three major browser vendors—Apple, Opera, and the Mozilla Foundation—formed the Web Hypertext Application Technology Working Group (WhatWG) to develop a new version of traditional HTML. Recently, the W3C has also noticed these activities and launched its own new generation HTML project. Many of the members of both parties are the same. The two projects are likely to eventually merge. While many details are still being debated, the broad outlines of the next version of HTML are already clear.
Web developers have been waiting for a new version of HTML (often called HTML 5, but also called Web Applications 1.0) since 1999, and now it's finally released. It maintains the original features of HTML: no namespaces or patterns. The element does not have to end. Browsers treat errors leniently. p is still p and table is still table.
If a web developer were frozen in 1999 and thawed now, he would encounter some new and confusing elements. Yes, familiar elements like divs are still there; however, HTML now also includes new elements like section, header, footer, and nav. em, code, and strong are still there, but meter, time, and m have been added. img and embed are still available, but video and audio have been added. However, upon closer inspection, he discovered that these elements were actually indistinguishable. Many of these elements were probably what developers needed in 1999 but didn't get. These new elements are easy to understand through simple analogies to elements he already mastered. In fact, they are very easy to master compared to Ajax or CSS.
Finally, when he turns on his 300MHz laptop (running Windows 98, which was also frozen in 1999), he may be surprised by how new pages appear in Netscape 4 and Windows® Internet Explorer® 5. Of course, these older browsers don't recognize the new elements and will ignore them completely, but the page will still display and the content will still be intact.
This is not a fictional story. HTML 5 is designed to degrade gracefully in browsers that don't support it. The reason is simple: we are all such "primitives." Browsers now have tabs, CSS, and XmlHttpRequest, but their HTML display engines are still stuck in 1999. Apart from a huge increase in the number of users, the Web has essentially made little progress. HTML 5 takes this into account. It currently offers some real benefits to web developers, and as browsers slowly upgrade, page viewers will gradually enjoy these benefits.
Let’s take a look at what HTML 5 has to offer.
(To be continued)