Use the World Wide Web as an example to illustrate the concept of resource sharing, client and server. What are the advantages and disadvantages of HTML, URLs and HTTP as core technologies for information browsing? Are any of these technologies suitable as a basis for client- server computing in general?

What will be an ideal response?

Web Pages are examples of resources that are shared. These resources are managed by Web servers.

Client-server architecture. The Web Browser is a client program (e.g. Netscape) that runs on the user's computer. The Web server accesses local files containing the Web pages and then supplies them to client browser processes.

HTML is a relatively straightforward language to parse and render but it confuses presentation with the underlying data that is being presented.

URLs are efficient resource locators but they are not sufficiently rich as resource links. For example, they may point at a resource that has been relocated or destroyed; their granularity (a whole resource) is too coarse- grained for many purposes.

HTTP is a simple protocol that can be implemented with a small footprint, and which can be put to use in many types of content transfer and other types of service. Its verbosity (HTML messages tend to contain many strings) makes it inefficient for passing small amounts of data.

HTTP and URLs are acceptable as a basis for client-server computing except that (a) there is no strong type- checking (web services operate by-value type checking without compiler support), (b) there is the inefficiency that we have mentioned.