web services,web application

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).

Answer 2

web app is user interface, access by humans, user can browse data , can submit and retrieve data. All user interactivity (the GUI) is done through web pages, but all data is stored and manipulated on the server.

Web service server-based application and meant for interaction with other programs. A web service is a way to expose some business logic you have over the internet. Say you got a module that connects to the database and does something. You can let other applications on the internet use this module of yours via web services. Web services uses SOAP over HTTP to invoke the request and retrieve the response in XML.