Due to New York traffic, I arrived at the event ten minutes late, but that's not the only reason I was left scratching my head and asking, "What the heck is Web services?" It turns out, it's actually a relatively new buzzword. I didn't get a simple explanation of Web services until shortly after IBM's initial presentation when I had a chance to speak with Beverly DeWitt, the Senior Manager for Lotus developer marketing in the Messaging and Collaboration business unit. Unfortunately, my hands were too full with complimentary soda and cookies to write down her explanation word for word, so instead I'll offer a quote from an article Beverly wrote entitled, "Why the IBM & Lotus Web Services Initiative Is Important to Customers." She explains the concept of Web services this way:

Web services is a standards-based approach to integrating applications running across distributed servers that are connected via an intranet, extranet, or the Internet. For example, if Server 1 knows how to process foreign currency conversions and an application on Server 2 needs that particular functionality, then it would be beneficial to let Server 2 tap into the function on Server 1 rather than having the developer re-create that functionality on Server 2. This notion of integrating applications that can be distributed over the net isn't a new concept, but Web services provides the means to do it easier, more securely, and without the complexity of writing a custom interface for each application.

This is an excellent article, by the way. If you want to learn more about IBM and Lotus Web services, you can find the article at http://www.lotus.com/news/news.nsf/public/D10C7A6AA924A6D085256A48006ED09D.

Web services are enabled by four open Internet technologies, some of which you may already be familiar with. Heavy use is made of XML (eXtensible Markup Language) in conjunction with WSDL (Web Services Description Language), SOAP (Simple Object Access Protocol), and UDDI (Universal Description Discovery and Integration).

According to Beverly, "WSDL is the XML description of a service that a Web server is offering. This description states what the service can do, the required input parameters, and what the service will return to the requester. SOAP is the protocol that the Web server uses to invoke a service. UDDI is an XML listing of the participating Web servers and the services offered by each."