Here i wana to add some basic stuff:

Agreed , its a ways by which your published application can be accessed accross the world and across the platform.

In short and more meaning full, its a programmable application which is accessiable via Standard Web Protocol and one of the web protocol is SOAP.

AS we know main two attributes of Web service is XML+HTTP.

SOAP use XML for data description and HTTP for tranporting your data.

I must say, SOAP work as an envolape which cover over messages and send and receive by different transport based on the address .

in the world of technology, this webservices help users to send and receive the information without any barrior of languages and platform.

Consumers of a Web Service do not need to know anything about the platform, object model, or programming language used to implement the service; they only need to understand how to send and receive SOAP messages (HTTP and XML).

• Web service is the way to publish application's function on web that can be accessible to the rest of the world.
• Web services are the components that can be used by other applications
• ASP.NET offers easy way to develop web services, just precede the functions with a special WebMethod ()> attribute in order them to work as Web Service.
• Web services are discovered using UDDI directory services.
• Web services are built on XML standard and use SOAP protocol that allows them to communicate across different platforms and programming languages.
• Web services platform elements are
  SOAP (Simple Object Access Protocol)
  UDDI (Universal Description, Discovery and Integration)
  WSDL (Web Services Description Language)
• The web services are built on internet standards that are not platform or language specific.
• The .Net framework provides in-built classes to build and consume web services.