Ajax introduction (Abbreviation: Asynchronous JavaScript and XML)

Link: http://hi.baidu.com/tommickey/blog/item/4270a1580eaccf82810a186e.html

Ajax is called "Asynchronous JavaScript and XML" (Asynchronous JavaScript and XML). It is a Web page development technology used to create interactive web applications. It mainly includes the following technologies Ajax (Asynchronous JavaScript + XML) Definition Representation Based on the Web Standard (Standards-based presentation) XHTML + CSS; Use dom (Document Object Model) for Dynamic Display and interaction; Use XML and XSLT for data exchange and related operations; Use XMLHttpRequest for asynchronous data query and retrieval; Use JavaScript to bind everything together. For more information, see the original document of Ajax author Jesse James Garret. Similar to DHTML or lamp, Ajax does not refer to a single technology, but organically utilizes a series of related technologies. In fact, some Ajax-based "derived/synthesized" (derivative/composite) technologies are emerging, such as "aflax ". Ajax applications use Web browsers that support the above technologies as the operating platform. These browsers currently include Mozilla, Firefox, Internet Explorer, opera, Konqueror, and safari. However, opera does not support XSL format objects or XSLT. Traditional Web applications allow users to enter forms and send a request to the Web server when a form is submitted. The server receives and processes the form and then returns a new webpage. This method wastes a lot of bandwidth because most of the previous two pages of HTMLCodeUsually the same. Because each application interaction requires sending a request to the server, the response time of the application depends on the response time of the server. This causes the user interface to respond much slower than the local application. In contrast, an Ajax application can only send and retrieve necessary data to the server. It uses soap or some other XML-based Web service interfaces and uses JavaScript on the client to process responses from the server. Because the amount of data exchanged between the server and the browser is greatly reduced, we can see applications with faster response. At the same time, a lot of processing work can be done on the client machine that sends the request, so the processing time of the Web server is also reduced. Ajax applicationsProgramAdvantages: 1. Improved user experience through asynchronous mode 2. optimized the transmission between the browser and the server, reduced unnecessary data round-trips, and reduced bandwidth usage 3. the Ajax engine runs on the client and undertakes part of the work originally undertaken by the server, thus reducing the server load for a large number of users. Comparison with traditional Web Applications   Http://baike.baidu.com/view/1641.htm