The third article in this series, "Web Services Part III: What Are Web Services?," provided some basic terminology used when discussing web services (SOAP, WSDL, UDDI, and so on). In this article, we discuss some characteristics of enterprise-level web services. Future articles will continue exploring related topics, including messaging systems, one of the cornerstone technologies for enterprise integration.
A quick browse of the two web services repositories, XMethods and SalCentral, illustrates that most of the published public web services so far are based on existing information-retrieval services such as stock quotes, weather data, and so on. While these services are interesting, it's highly unlikely that corporations (or even individual users) would pay for these services, since they're too granular.
Broadly speaking, web services can be classified into two categories:
- Synchronous web services
- Asynchronous web services