.NET Framework Essentials, 3rd Edition

Chapter 6. Web Services

W eb services allow access to software components through standard web protocols such as HTTP and SMTP. Using the Internet and XML, we can now create software components that communicate with others, regardless of language, platform, or culture. Until now, software developers have progressed toward this goal by adopting proprietary componentized software methodologies, such as DCOM; however, because each vendor provides its own interface protocol, integration of different vendors’ components is a nightmare. By substituting the Internet for proprietary transport formats and adopting standard protocols such as SOAP, web services help software developers create building blocks of software, which can be reused and integrated regardless of their location.

In this chapter, we describe the .NET web services architecture and provide examples of a web service provider and several web service consumers.

Web Services in Practice

You may have heard the phrase “software as a service” and wondered about its meaning. The term service, in day-to-day usage, refers to what you get from a service provider. For example, you bring your dirty clothing to a cleaner to use its cleaning service. Software, on the other hand, is commonly thought of as an application, either an off-the-shelf product, or a custom application developed by a software firm. You typically buy the software (or in our case, build the software). It usually resides on some sort of media such as floppy diskette ...