What are Web Service | Basic | Introduction

What is Web Services?

 Web Service | Basic introduction | Why | How | Where 

•  Web service is used to share the data between applications.

 Will try to understand this through an easy example:

Example : If a HDFC card holder, wants to withdraw money from SBI or ICICI banks atm, how this   works, will understand the complete concept using this example, now question is:

1. How the other bank ATM's will come to know the information of HDFC bank card holder?
2. If they do not have the database of HDFC bank card holder, how the transaction take place?

 
Answer 1. In case the HDFC card holder uses the SBI atm, the atm will verify the all details of card using HDFC bank application, it means during the transaction their is a communication between these two bank's softwares.

Answer 2. Bank do not share the details with any other bank, means the validation take place at original bank site only, it means here also their is a communication needed for the successful transaction.

Basically how this communication are responsible for the transaction, lets understand this:

1. A HDFC card holder inserts a card into SBI atm, atm checks the bank information of card, and ask HDFC software to validate the user. 
2. HDFC software sends the response to SBI bank, that user is valid.
3. The same way, user enter the amount to be withdraw, the same communication starts again, SBI atm ask HDFC software to check the available amount in users account.
4. After checking whether their is enough amount in users account, HDFC banks sends the response to the SBI atm.

In this way this process happens, now we have observed that there is a continue communication(sharing of info.) between two software , which are not related to each other, 

 After this,we conclude that, there is continuous sharing of data in order to complete the transaction, now question is:

How the data is shared between the application?? ------> The data is shared in XML format

for time being just remember that the XML is something, in which form the data is shared between the applications.

In next tutorial will see

1. Basic architecture of Web Services.
2. Component in Web Service.(WSDL/UDDI/STUB/SKELETON/SOAP/HTTP)
3. What are these component are responsible for.
4. What are the various Web API's available.

Note: This communication request and resonse are taken care by web service created to do the specific task.

Smiles !