1th Chapter-web Application Development Overview

1.1 Network Program Development Architecture: C/S,B/S

11.1 c/s structure :

Client/server, which is the client/server structure. It reduces the communication overhead of the system and the client needs to install the dedicated client software. Before the 2000, the dominant position.

11.2 b/s structure:

Browser/server, which is the browser/server structure. Firefox accesses the server via a browser such as IE. It saves costs and has become the first choice for today's application software.

11.3 Comparison of the two structures  

1. Cost of development and maintenance

The cost of development and maintenance of C/s is higher than b/s. With the C/s structure, the version of the update and installation will have to require the client hands-on operation. and b/S structure

Only needs to be updated on the server, and the customer only needs to log back on to the system to use the latest version.

2, Client load

Clients of C/s structure need to interact with users, collect user information, and process the data returned by the server. The program that causes the client is getting larger. This one

The maintenance of the software has caused a lot of trouble. b/S is not the same, the logical portion of client transaction processing is given to the server. The client only needs to be displayed.

This also brings the server to "crash" easily, so many units are backing up multiple servers. Case.

3, security

c/S In this respect, it is through strict management distribution software, to the use of the system. Unlike b/s, many people use and are not fixed.

Summary: Overall b/s advantage is bigger, with the technology mature, b/s will gradually become more powerful, more people use.

1.2 Web Introduction   

Web is the abbreviation of WWW, extended to the "Global Network", for ordinary users, it is only the environment of Internet use. For website makers or designers,

It involves the front desk, page production, backstage, database and other a series of technology collectively.

1.2.1 What is a web

The web is a kind of information system based on hypertext work. It provides a wealth of information resources. There are the following three kinds

• Hypertext (hypertext)

Hypertext is a kind of global information structure. It establishes a connection between different parts of the document through keywords. allows information to be searched interactively .

• Hypermedia (hypermedia)

Hypermedia is the combination of hyper-text and multimedia in the information environment. With Hypermedia, users can jump from one text to another, play video, audio, etc.

• Hypertext Transfer Protocol (HTTP)

HTTP is a hypertext protocol that transmits over the Internet.

How the 1.2.2 Web works

Four steps to a web workflow

1. The user enters the URL in the browser and sends an HTTP request to the Web server.
2. Web server receives requests to find related information resources
3. Responding to requests, returning resources
4. The browser displays the results to the user

1.2.3 The history of Web development

Since 1989 Tim Berners-lee (Tim Berners Lee) invented the World Wide Web, the web has undergone three stages

1, Static document (Web 1.0)

Mainly used for static web page browsing, can only display simple text information .

2, dynamic page (Web 1.5)

A variety of programs and logic controls have been added to traditional static pages, enabling dynamic and personalized interaction, using network programming techniques to create

Also referred to as dynamic pages, the suffix is typically,. jsp. php. ASP. The static page is,. htm. html. shtml, etc.

3,web 2.0

User-centric, through the Network application to strengthen the network of communication between users and cooperation. Web technology mainly includes blog, Weibo (Twitter)

RSS, Wikipedia, SNS (social network), p2p,lbs (geo-information services).

1.3 Web Development Technology

Web development technology is divided into client technology and service-side technology

1th Chapter-web Application Development Overview