That's Not ASP!
Web services are completely new to ASP.NET, so you've been treated to something new today if you're a traditional ASP developer. However, the ideas behind Web services, such as intercommunication of various disparate systems, are similar to COM objects. (See yesterday's lesson for more information on COM objects.)
The goal of COM was to allow developers to build applications composed of various components. Because these components relied on the COM protocol to communicate, they could be developed in different programming languages. COM suffered from being confined to a specific platform, though Windows.
Web services go beyond COM because they don't adopt any proprietary protocols or binary formats of communication between objects. Instead, Web services are completely based on the open standards XML and HTTP, which means they truly allow interoperability between any disparate systems.
The concept of deploying applications over the Internet as services isn't completely new either. Previous attempts, similar to COM, have relied on complex proprietary standards, which limited their usefulness. It's the simplicity of XML and HTTP that makes Web services so effective.