Web service VS Web application

According to Wikipedia:
"A web application is an application that is accessed over a network such as the Internet or an intranet."


When we consider this definition we can easily say that any application which are being provided to the user on the WEB is web application. The web application had started getting appraisal mostly in the 90s due to what we call today DOT COM boom. The internet was spreading at a very high rate and every one was trying to exploit their chances. This provided a very huge market and companies like amazon and ebay came into picture. To do so they require some way to interact with the end users, this was provided by the web applications.


Whereas web application is used by the end users to take the benefit of the capabilities of the internet, The Web Services are not used by these end users directly They are used by the various application which provides these services to the end users.


When there was no web services there were a lot of problem regarding providing services to the end users. Many of the techniques has been devised to overcome these problems,e.g., screen scrapping. The initial question was how to fulfill the need of the end user, the answer to this was the use of CORBA or DCOM. But the problem here was the interoperability.


With the need to resolve the problem of interoperability, the XML came into picture and was widely accepted due to its capability to exchange the information without any constraint of data, platform etc. This XML played a great role in the development of web services as these give the freedom to interact across boundaries. This was followed by the development of new protocols and Languages specifically for web service. These were the SOAP, WSDL and UDDI.


Now a days many of the web application are using the web services to provide services to the user in very efficient manner. They are taking services from different sources and pass these to the end user. 


In the conclusion of this, the web application can be seen as the interface through which the end user can access the benefits of various services(web services) where as the web services can be seen as the method to provide these services. The web services actually has made the web application very sophisticated which can improve according to the change in the end user requirements.  

Web Services

When we talk about web services the first question to be answered should be what are services and what is the need of web service.
Lets begin with a simple example:

The Knowledge process outsourcing may be a simple example of how the web is exploited to provide service.
When we talk about KPO it is about providing the education to the students who are not able to get to a good teacher due to some constraints, the tutoring here is the services being provided by the KPOs. The KPOs use the services of the teachers and provide it to the students. This is how web services work.

Lets come to other example coming to online payment system. This may be used for paying money to any purchase and may be required by different vendors and in turn these vendors may require to be using services of many banks. Here the role of online payment system come into picture. This system take the services of different banks and bundle it together to provide the services to these vendors.

The same may apply to amazon which takes the order for the different stuffs or ebay which also applies similar thing to provide the services.

These  are the places where the role of web services come into picture:
Web service is defined as the capability that are available to other application by various Industry Standards, API and Protocols.
In this sense, the web service implement these services to be provided to various applications which in turn is provided to the end users.

Now comes, How it helps. So the one very important benefit of this is the infrastructure required had reduced drastically. Now we can combine the services provided by several sources to one and exploit the benefit of the services. And as these services are provided on the WEB this can reach to a large mass of people.

Coming to the Technical point of view,  the web services use various technologies designed specifically to support it. These are SOAP, WSDL and UDDI.

Simple Object Access Protocol (SOAP) is the XML based mechanism for exchanging the information. This is also used to implement Remote Procedure Calls(RPC). This helps in making the data to be exchanged in a format which is independent of the different platforms, languages etc.
Web Service Description Language(WSDL) is an XML-based language  for describing web services. This describes services as the collection of ports. data are  implemented as messages which are exchanged between different ports which represents various services.
Universal Description, Discovery and Integration (UDDI) is a specification for a registry of information for web services. This is used to publish about the web services which are available and dicver it if some one needs it.

Difference Between Web Application and Web Services

First i will briefly describe about Web Application.
A Web Application is a dynamic extension of a web or application server or you can say it as a website where we can log on to it and browse.
A Web Application actually consists of web components,static resource files such as images and helper classes and libraries.
There are basically two types of Web Applications.
First one is called Presentation Oriented Web Application which generates interactive web pages containing various types of markup languages like XML and the dynamic content in response to requests.
Second one is Service Oriented Web Application which implements the end point of a web service.
So to conclude lastly Presentation Oriented Applications are often clients of Service Oriented Web Applications.

So now about Web Services which is a software component that is described via WSDL and is capable of being accessed via standard network protocols such as SOAP over HTTP.
Web Services are self-contained (like independent unit),modular applications which can be described,published,located and invoked over a network like to expose some business logic you have over the internet.
As i have already mentioned in this blog Web Services are meant for developers but not for novice users.
Web Services can be used to realize Service Oriented Architecture which is explained later in this blog.

Web Services

Web Services are those services that gives a path to communicate or we can say avail and provide facilities from which we can communicate with service provider or between application etc in required manner, that allows to communicate data and can convert applications into Web-applications, basically these are application components that can communicate using some protocols.

Web services are self describing and can provide services without using browser or html, whole data and respective applications are runs on server and dealing with client or software or application in terms of request .Web services are discovered using UDDI (Universal Description, Discovery and Integration).

Web services can be used by other applications, operating system, over web applications for avail or provide services or we can say facilities according to pre-configured manner as required where XML is the basis for Web services and the basic Web services platform is XML + HTTP. Where XML provides a language which can be used between different platforms and programming languages and deals with messages and functions.

There are three main elements of web services are :

• UDDI (Universal Description, Discovery and Integration)
• WSDL (Web Services Description Language)
• SOAP (Simple Object Access Protocol)

Web Services

The definition about Web Service is actually a software component stored on one computer that can be accessed via function calls by an application on another computer over a network.

                                          

HTTP protocol facilitated Human-to-Application like communications and there was an increasing demand for Application-to-Application communication with the traditional existing techniques.HTTP was not adequate for more complex operations like remote operation.

                                                                                                         

In Late 1999,Microsoft published SOAP (Simple Object Access Protocol) an XML-based protocol and then IBM support came into picture in early 2000 and the term Web Services was coined several months later,when IBM,Microsoft,and Ariba jointly published the Web Services Description Language (WSDL).

Web Service normally resides on a server.The term coined for making a web service available to recieve client requests is known as Publishing a Web Service and using a web service from a client application is known as Consuming a Web Service.Web Services have the characteristic like software portability and reusability in applications that operate over the internet. 

Some of  the Web technologies used are as follows.

XML (Extensible Markup Language)

SOAP (Simple Object Access Protocol) which allows client to call remote service.

WSDL (Web Services Description Language)

WSIL (Web Services Inspection Language)

UDDI (Universal Description,Discovery and Integration) a standard used for publishing or query web services.

                                                    
Web services are meant for developers but not for novice users.Web services are platform and language independent.Web services have important implications for business to business transactions.

Web Services

Web services are services deployed on internet.Web services use standard network and application interfaces and protocols.Web services expose their capabilities to client application not their implementation which makes it platform independent and makes it compatible with client applications.

Web services cut down cost by focusing on value added contributions and uses third party applications.It reduces errors from complex large monolithic application and also reduces time-to-market. The technology that form the foundation of web services are SOAP,WSDL and UDDI.
 
web services uses XML based language like WSDL to describe services.WSDL  is a client application that determines location of remote web services and describes how to access and use each functions.

The protocols were developed to leverge XML and information exchange. Web Services uses SOAP protocol which  uses XML-based mechanism for information exchange between application within a distributed environment.

HI ALL

welcome to SOA...
All of the Members are requested to add their Full Names as the Labels in their post

All the best