Question

what are web services(Rmi,ejb,soap)? what is the difference between web services and web application? Is it possible to implement web services in web application?

Answer 1

A web service is a way to transmit/expose information in such a way that a Web Service client, which can created in a server script or from a stand-alone program, can call the service for what it wants using methods and functions defined by the service.

One of the benefits of a web service is that it abstracts these methods and functions (and variable types) in such a way that any language that “speaks” web services can use it’s own syntax to interface with the service (thus making it cross-language).

Another benefit is that it uses the HTTP protocol (usually transmitting via XML or JSON, but not necessarily either), so it’s also cross-platform.

A huge benefit is that an application that typically requires very specific knowledge and software can “expose” information via a web-service. So if you’re corporate mainframe has tons of top-secret data that typically requires a terminal client, etc, to get data, certain data can be accessed via a Web Service so that you can have your HR department download and upload timesheet changes from a web site.

A web app can certainly include a web service, but they are not the same thing. You can make a web service using PHP or .NET, and then have a web app written in either language interface with that service, but a web app tends to be an interface for the site you’re on, while a web service is about getting info to and from other apps (web or not).