19th century is the era of railways, 20th century is the era of expressways, and 2 1 century is the era of networks. The rapid rise of the Internet and its rapid development around the world make the World Wide Web (WWW) an efficient global information distribution channel. This technology is entering thousands of households at a rapid speed, and it will turn the earth into a small village. The network era is coming.

We are busy building the world we live in, and we are building a replica of our physical space in cyberspace. Even banks can deposit money online, and churches should be set up in online prayer places. The Internet has penetrated into all walks of life, and more and more information is running on the information superhighway. With the continuous development of internet technology and people's demand for geographic information system, it has become an inevitable trend of GIS development to publish and publish spatial data on the Web by using the Internet to provide users with the functions of browsing, querying and analyzing spatial data. Therefore, WebGIS, a geographic information system based on Internet technology, came into being.

WebGIS is the product of the application of Internet technology in GIS development. GIS has been expanded through WWW function and has really become a tool used by the public. Internet users can browse the spatial data in WebGIS site from any node of WWW, make thematic maps, and conduct various spatial retrieval and spatial analysis, thus making GIS accessible to thousands of households. WebGIS has the following characteristics:

(1) Globalized Client/Server Application Internet users can access various GIS services provided by WebGIS servers at any WWW node in the world, and even update GIS data around the world.

(2) Really Popular GIS Due to the explosive development of the Internet, Web services are entering thousands of households, and WebGIS provides more users with opportunities to use GIS. WebGIS can be browsed and queried through a general browser. Additional plug-ins, ActiveX controls and Java Applet are usually free, which reduces the economic and technical burden of end users and greatly expands the potential users of GIS. In the past, because of the high cost and technical difficulty, GIS often became a professional tool owned by a few experts, which was difficult to popularize.

(3) Good scalability WebGIS can be easily integrated with other information services in the Web to establish flexible GIS applications.

(4) Cross-platform features Before WebGIS appeared, although some vendors provided corresponding GIS software versions for different operating systems (such as Windows, UNIX and Macintosh), there were not many GIS software with cross-platform features. WebGIS based on Java can be written once and run anywhere, which fully demonstrates the cross-platform characteristics.