What is meant by Web Services?

Question

Can anybody tell me what is meant by web services?
How do they work?
and more information about it.

Answer 1

Web services are typically application programming interfaces (API) or web APIs that can be accessed over a network, such as the Internet, and executed on a remote system hosting the requested services. --Wiki

Wiki has a good article on Web Services, you'll find a load of information there.

http://en.wikipedia.org/wiki/Web_service

Answer 2

in web application web-service used for transfer data using Ajax technologies without refreshing all page.

also i prefer to you this article with sample Create a JSON WebService in ASP.NET 2.0 with a jQuery Client link text wroted by Ajay Singh link text

Answer 3

As Andrew Tanenbaum and Maarten van Steen say in Distributed Systems - Principles and Paradigms, 2nd Edition: "a Web service is nothing but a traditional service (e.g., a naming service, a weather-reporting service, an electronic supplier, etc.) that is made available over the Internet". The main idea is that you have a client application that can use services provided (published) by a server application.

There are a couple of important things you should look into: one is the directory service which stores service descriptions, which should adhere to the UDDI standard. Another thing is that web services are described by the means of formal language (WSDL). And last, but not least, you need to specify how communication takes place: SOAP is a widely (probably most well-known) protocol in this sense. Also, as can be noticed, be really careful about the standards (protocols, formal description language etc.), when implementing web services.

The ideas above have been taken from the aforementioned book (Distributed Systems - Principles and Paradigms, 2nd Edition, Andrew S. Tanenbaum, Maarten van Steen, 2007). For more programming language oriented books, you can check "Java Web Services: Up and Running" by Martin Kalin, O'Reilly, 2009 (did not read this but it is by a good publisher and it is new) and I am sure there are a lot of other good books out there.

Answer 4

Fahrenheit to Celsius - Simple Example Web Service (ASP.NET)

You can get started with Web Services @ W3Schools.com.

Your first C# Web Service - Code Project

And most of your questions are answered in a 15seconds article.

Answer 5

If you are familiar with calling a subroutine (method/procedure/function/etc) with parameters and get a result back, then "web services" is one of many ways to call a subroutine located "elsewhere" and get a result back. "Elsewhere" is typically on another computer under the control of somebody else but you.

It has been tried several times before but I believe that Web Services have become so popular due to several reasons:

• The communication can be done over http (like a browser). This means that a lot of infrastructure can be reused, and as http is simple, that infrastructure can be simple. This includes proxies, firewalls, debug tools etc.

• Web Services include a "contract" - WSDL - saying exactly which things are provided, where they are, and what arguments they take, and what is returned. That contract allows building helping tools, proxies, creating a tool that simulates the other end, and much more.

• Microsoft likes it. This results in good support on Windows, which gives many programmers an easy way in.

But, the answer to your question is "web services are subroutines located on other computers".

Answer 6

Web services are just like a kind of framework, that you access over the Internet. That can be used for authentication, single sign-on, data access, etc. For instance, imagine a Twitter client. It can be a web application, a desktop application, or a mobile application. They all need to authentify a user, get the timeline, get the user tweets, and allow the user to post a new tweet. The aplication receives the data from the user, and transmit it to Twitter, by their web service. This is done by calling an URL on twitter.com with some parameters, depending on the web service format (soap, rest, etc). Then Twitter can process the action. Web services allows applications to use, interact with, and communicate with other aplications. That way, you van have many apps, but only one data source.