Basics of Web Services

In this article, we aim at learning the basics of web services and understand how does web service works.
1.   Web services are the easy way to create communications between different applications of different platform.
2.  Web Services extend these models a bit further to communicate with the Simple Object Access Protocol (SOAP) and Extensible Markup Language (XML) to eradicate the object-model-specific protocol barrier.

Components of Web Service:
All the standard Web Services works using following components
  1. SOAP (Simple Object Access Protocol)
  2. UDDI (Universal Description, Discovery and Integration)
  3. WSDL (Web Services Description Language)
SOAP (Simple Object Access Protocol):
SOAP is an XML-based protocol to let applications exchange information over HTTP. Simply, SOAP is a protocol for accessing a Web Service.
  1. It is a communication protocol and it is a format for sending messages.
  2. It is designed to communicate via Internet (W3C standard)
  3. It is platform and language independent
  4. SOAP allows you to get around firewalls
WSDL (WebServices Description language):
It is a W3C standard used to describe and locate the web service in XML language format.
UDDI (Universal Description, Discovery and Integration):
  1. It is a directory for storing information about web service
  2. It communicates via SOAP
  3. It is built on .NET platform
Why web service?
  1. Interoperability
  2. Usability
  3. Deployability
  4. Reusability
For more details on the advantages and disadvantages refer this MSDN article:

To know about creating a web service using ASP .NET read this article.
To know about consuming a web service using ASP .NET read this article.