“This is the first day of my participation in the Gwen Challenge in November. See details of the event: The last Gwen Challenge in 2021”.
1. Understand the WEB
1. 1
Web pages are made up of text, images and hyperlinks. Of course, in addition to these elements, a web page can also contain audio, video, Flash, etc.
1.2. Browser
A browser is a platform for displaying and running web pages. Common browsers include Internet Explorer, Firefox, Google (Chrome), Safari and Opera. We call them the Big Five browsers.
Internet Explorer is probably the browser you’re most familiar with, but it’s way too slow.
We can check the current browser market share through Baidu’s Traffic research institute. In 2008, the well-known Internet giant Google released its first browser, Chrome. Like Wang Sicong, there is no way, was born the family is rich second generation officer second generation ah, the background is too strong, and indeed the innate ability is unique. From Google, only I can’t beat; A unified river’s lake, thousands of generations.
1.3 common browser kernels
The browser core is called the Rendering Engine, which is currently called the Rendering Engine. He is responsible for reading the content of the web page, collating the information, calculating the display mode of the web page and displaying the page. There are a variety of browsers, but the main popular ones are the following:
| The browser | The kernel | note |
|---|---|---|
| IE | Trident | IE, Cheetah security, 360 speed browser, Baidu browser |
| firefox | Gecko | Unfortunately, these years have been declining, slow to open, upgrade frequently, pig like teammate Flash, god like opponent Chrome. |
| Safari | webkit | Many people now mistakenly refer to WebKit as the Chrome kernel (even though the Chrome kernel is blink). Apple felt like she had been robbed of her wife. She cried and fainted in the toilet. |
| chrome | Chromium/Blink | The Blink rendering engine (browser core) was developed in the Chromium project and built into Chrome. Blink is actually an offshoot of WebKit. Most of the latest versions of domestic browsers use the Blink kernel. Secondary development |
| Opera | blink | Now follow Chrome with the Blink kernel. |
The mobile browser kernel is the core of the system’s built-in browser. He has two camps:
- Android phones, the highest use is Webkit kernel, most domestic browsers declared their own kernel, basically also belongs to Webkit secondary development.
- On iOS and WP7, due to system reasons, most of the systems have their own browser kernel, usually Safari or IE kernel Trident.
1.4. Web Standards
Web standards are not a single standard, but rather a collection of standards developed by the W3C organization and other standardization organizations. W3C is the most famous standardization organization in the world. Since its establishment in 1994, it has published nearly 100 web standards and made outstanding contributions to the development of the Web. The W3C is like the United Nations in the real world.
1.4.1. Why Follow WEB Standards
From the above browser kernel differences, we know that they display the page or layout slightly different, so we need to develop a unified markup to display the same content
1.4.2 Benefits of Web Standards
Following web standards has many advantages besides making the pages we write more standard and consistent:
- Let the development of the Web broader prospects.
- Content can be accessed by a wider range of devices.
- More likely to be searched by search engines.
- Reduce the cost of web traffic.
- Make the site easier to maintain.
- Improve page browsing speed.
1.4.3 Composition of Web standards
Web annotation mainly includes Structure, Presentation and Behavior. Generally speaking, it is HTML, CSS, JS.
| standard | instructions | note |
|---|---|---|
| structure | Structure used forWeb page elementsTo sort and categorize, we are mainly learning HTML. |  |
| performance | Represents the layout, color, size, and so on used to set web page elementsPresentation styles, mainly refers to the CSS |  |
| behavior | Behavior refers to the definition and model of web pagesinteractionWrite, we mainly learn Javascript |  |
1.4.4,
- Web standards have three layers of structure: structure (HTML), presentation (CSS), and behavior (javascript).
- The structure is similar to the human body, the performance is similar to the human dress, the behavior is similar to the human behavior.
- Ideally, all three layers are kept separate and placed in separate files.
1.5. The development of HTML5
1.6, XHTML
XHTML (English: eXtensible HyperText Markup Language (XHTML), is a Markup Language that behaves like HTML but is syntactically more rigid. In terms of inheritance, HTML is based on standard General Markup Language (SGML) and is a very flexible markup language, while XHTML is based on Extensible Markup Language (XML), a subset of SGML. XHTML 1.0 became a W3C recommendation on January 26, 2000.