Web service is one of the greatest technologies in the Internet world; it can be used to connect businesses with each other and clients in a standard way using XML (Extensible Markup Language), SOAP (Simple Object Access Protocol), WSDL (Web Services Description Language) and UDDI (Universal Description, Discovery and Integration).
XML is used for structuring the data, SOAP is used to transfer the data, WSDL is used for describing the services and UDDI is used to get a list of services available. Web service allows applications to communicate with each other without worrying about hardware systems, operating systems and programming languages.
Unlike the older model, web service does not provide a user interface but exposes the business logic, which can be programmed, and hence the user is free to add his own interface to the application.
Google is one of the websites that have provided a public web service allowing applications to use features like search and spell checks. We shall now see how we can use these services in our applications using Visual Basic .NET.
But before we can access Google’s web APIs we will have to create a Google account and obtain a license key which will allow us to run about 1000 automated queries a day. Please visit http://www.google.com/apis/ to create a Google account. Once you have entered your email and password, Google will mail you a license key, which we will use in our application.