HTML, XHTML, HTML5 differences and connections

HTML (hypertext Markup Language, Hypertext Markup Language ), in the learning of HTML is also exposed to a concept--www, this often used, but do not know the truth. Of course, you need to know about HTML and its past and development.

Basic concepts

WWW (World Wide web, www) is an internet-based, global, interactive, multi-platform, distributed information resource network. It is a hypertext file (with connection and multimedia objects) that is described in HTML language.

The URLs we see most, or the URLs we use in our memory, are probably all www,www 3 basic components, namely URLs (Universal Resource Locators, unified Resource Locator ), HTTP (hypertext Transfer Protocol, Hypertext Transfer Protocol) and HTML (hypertext Markup Language, Hyper-text markup Language)

Url

URLs provide a uniform way and path to access resources on the Web, making the site that users want to visit unique, which is equivalent to each of us having only one ID. It represents the type of each file that the link points to and its exact location.

You can also understand that a URL is the only way you get a resource location or access method, as long as you know the URL of the resource can get the address, and the resource operation.

There are two ways to access URLs: FTP and HTTP

For example

And

HTTPHTTP is a data transfer protocol on a network that is designed to transmit information that is provided in hypertext (hypertext) or hypermedia (hypermedia) Form. is a detailed regulation of the browser and the World Wide Web server communication between the rules, through the Internet to transmit the World Wide Web document data Transfer Protocol.

HTTP works on TCP protocols in the TCP/IP protocol architecture.

Both the client and the server must support HTTP to send and receive HTML documents and interact on the World Wide Web.

(Most of the above is Wikipedia content--http)HTMLThe HTML language is a type of text, a markup language that relies on interpretation, that is, a language that most computers can recognize. The use of languages on the World Wide Web is generally HTML language. HTML is a markup language, so he will have a lot of markup elements, the most basic file structure is as follows:

        Therefore, in order to learn HTML, it is necessary to master the knowledge of certain markup elements. such as title text markers 



What are HTML4, XHTML, HTML5?when you learn HTML, and when you look at other blogs, there is a lot of HTML or XHTML, and I don't know if they're just different names.   And then we looked at the data for a comparison. 
in the early days of HTML development, before the creation of World Wide Web Consortium, Web Consortium, many of the standards of HTML were very irregular and the browser was not very demanding on HTML, so this continued   This led to the HTML writer writing a large number of HTML pages that contain errors. later, the web was also aware of this error, and that this is the fundamental issue of the Internet, should be addressed.   In order to standardize html,w3c with XML, the XHTML1.0 standard is established, but it only uses XML requirements to standardize HTML. The XHTML can be understood as html+xml. 
learn to use when the beef brisket div+css In fact can be said to be xhtml+css.   
HTML4 is currently the most widely used Internet standard, and he is born in about 1999 years.      It still plays an important role. 
HTML5 new features: 1. Canvas elements for painting 2. Video and audio elements for media playback 3. Better support for local offline storage 4. New special content elements     , such as article, footer, header, nav, section 5. New form controls, such as Calendar, date, time, email, url, search. one of its biggest features is that it doesn't break existing Web pages. Although HTML5 adds many new features, it is not universally supported by browsers, so other HTML is important and still in use. 

here is a very interesting comic, interested to see《confusing Markup Language XHTML2/HTML5 comics "Reference blog: http://autit.blog.163.com/blog/static/13804284420125710238652/
HTML, XHTML, HTML5 differences and connections