最近几年来，地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持，如城市管理、区划、环境整治等等，地理信息成为信息时代重要的组成部分之一； “数字地球”概念的提出，更进一步推动了作为其技术支撑的GIS的发展。 与此同时，一些学者致力于相关的理论研究，如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面，并且这两个方面构成了相互促进的发展过程。
Hypertext markup language (English: HyperText Markup Language, HTML) is a standard markup language for creating web pages.
You can use HTML to build your own WEB site, and HTML runs on the browser and is parsed by the browser.
In this tutorial, you will learn how to use HTML to create a site.
HTML is easy to learn! I believe you can learn it soon!
This tutorial contains hundreds of HTML instances.
Using the editor of this site, you can easily modify HTML online and view the running results of the instance.
注意： For Chinese pages, you need to use <meta charset=”utf-8”> Declare the code, otherwise there will be garbled. Some browsers (such as 360browser) will set GBK as the default encoding, then you need to set it to <meta charset=”gbk”>。
Suffix name of the HTML document
.html
.htm
There is no difference between the above two suffix names, and both can be used.
HTML instance
Hundreds of online instances are included in the HTML manual, and you can edit and view the running results online.
HTML reference manual
In the rookie tutorial, we provide a complete HTML reference manual, including tags, attributes, colors, entities, and so on.
HTML/CSS/JS online tool
HTML/CSS/JS online tools can edit HTML, CSS, JS code online and view the results in real time. You can also save and share high-quality code: https://c.runoob.com/front-end/61