Stages of Web evolution Table 1 summarizes the main stages through which the web has evolved. Stages 2 and 3 reflect the current stage of development of the web. XML makes it possible to add semantic information to a HTML document so that trading partners can understand the meaning of various fields in the document. Figure 1 shows a common model of how the web operates to provide interactive services such as shopping, database access, etc. Client connects to server and downloads a form.
Client fills in information on the form and submits it.
CGI program on the server processes the form. Server sends reply to client. While it works very well for a variety of applications, there are other instances where it is not so effective. In particular, some of the problems are as follows. First, it is not always possible to establish a connection between the client and server either because the underlying network is unavailable or the server is overloaded.