What is browser, B/S structure and C/S structure
Source: Shangpin China |
Type: website encyclopedia |
Time: June 16, 2014
Browser means it can display Website production The HTML file content of the server or file system, and a software that allows users to interact with these files. It is a client program that people use most frequently on the Internet. 1. Internet browser Web browser is a kind of client tool software for accessing Web server, which can be used to access the Internet and obtain information conveniently under a friendly interface. The basic purpose of Web browser is to let users search, query, mine and obtain various resources on the Internet on their own computers. As the Internet is in the rapid development stage, the Web is given new meaning by people who use it every day, making the functions of the browser constantly expand and update. The following is a brief introduction to several products that have played an important role in the browser arena and have made brilliant achievements. Some may be very familiar with them, while others have become history. (1)NCSA Mosaic In 1993, Marc Andreessen of the National Center for Supercomputing Applications (NCSA) at the University of Illinois and his colleagues developed a software that can interpret HTML documents on the Web and display the information contained in HTML documents in a unified way. This is the first browser Mosaic that can display pictures, as shown in Figure 6-14. This is the first real Web browser, which was first run in the X-Windows graphical environment of the Sun workstation. Later, NCSA launched the Macintosh and Windows versions of Mosaic. At present, no one has updated NCSA Mosaic, and its source code has already been disclosed. Every competent programmer and every company can use it for further development. (2) Netscape Navigator In April 1994, Marc Andreessen and SGI founder James H. Clark co founded T Netscape Communications (Netscape in Chinese), and Marc Andreessen served as the vice president of technology. Under his leadership, Netscape Communications Company has made a lot of improvements on the basis of Mosaic, and developed a new browser Netscape Navigator, which provides a new type of browser with Mosai. A similar but more practical graphical interface is shown in Figure 6-15. Its performance has been greatly enhanced in all aspects. It is the first browser to quickly display text and graphics, and the first browser to allow viewing the top of the page before receiving a full page of documents. Navigator supports News Group, and also supports HTTP, FTP, and Gopher in the same window. More importantly, it supports HTMI enhancements and improves the design of the entire Web site. (3) Microsoft Internet Explorer In August 1995, Microsoft Internet Explorer 1 0 is released. It is referred to as IE 1 for short 0. At that time, it was a simple "modified version" based on NCSA Mosaic, without adding more functions and features. It did not support Java and plug-ins, and its browsing speed was also very slow. August 1996, IE 3. Official release. This version provides support for HTML table customization, framework and more HTML elements, as well as support for script language and e-mail reader. For ActiveX control functions that will deeply affect computer security in the future, IE 3 0 started supporting. In October 1997, Microsoft released T IE 4.0 and bundled it with its Windows 98 operating system. Since then, Microsoft has continuously introduced new versions of IE. IE 8., released in March 2009. Significant improvements in functionality and security. On September 17, 2010, Microsoft released T IE 9 0 Beta. At present, browser software is extremely rich. Common browsers on PC include Internet Explorer, Firefox, Safari, Opera, HotBrowser, Google Chorrne, GreenBrowser, Avant browser, 360 security browser, Window of the World, Tencent TT, Sogou browser, and Surf browser. 2. C/S structure Client/Server (C/S) is a mature technology developed in the 1990s. It divides applications into two parts: client and server. The C/S structure is shown in Figure 6-16, where the specially developed client software is exclusive to each user and is responsible for performing the foreground functions. Such as management of user interface, data processing and report request; In the server part, multiple users share information and functions, and perform background services, such as managing shared peripherals, controlling the manipulation of shared databases, and receiving and responding to client requests. The main features of C/S mode are: request/response mode; Take message exchange as the communication mode; Process based service access; Services are focused on specific servers. The software architecture of traditional C/S mode is a two-layer structure under the "fat client" structure, that is, a large number of transaction processing logic, computing tasks and interface display are completed on the client. The client has a heavy workload. If transaction processing logic is separated and an intermediate layer called application layer is introduced between client and server, a three-layer C/S structure of user interface, intermediate business logic and back-end database server will be formed, as shown in Figure 6-17. In the three-tier C/S structure, the client function can be further weakened, making it a "thin client". 3. B/S structure Browser/Server (B/S) structure is an application software structure after the rise of the Internet. Different from the C/S structure, client software is no longer dedicated. Under the B/S structure, the user work interface directly uses the Web browser, a small part of transaction processing is implemented in the front end (Browser), and the main transaction processing is implemented in the server, This greatly simplifies the client, reduces the cost and workload of system maintenance and upgrade, and reduces the overall cost of users.
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