Web services are a key part of the .NET Framework, but there is still confusion about their purpose and use. This chapter explains web services and their role in Microsoft's vision of the programmable Web. It also discusses the technical standards that allow web services to function, such as WSDL and SOAP. To understand web services, it's important to recognize the limitations of current distributed application architecture. Many internet applications are "monolithic," combining various services behind a single user interface. While this model is successful, it has several drawbacks. Monolithic applications are time-consuming and resource-intensive to create, often tied to specific platforms or technologies. They are difficult to extend and enhance. Integrating multiple applications is a complex task, often requiring custom work. Reusing application logic between different applications is also challenging, especially when the applications are from different companies or use different programming languages. The situation is similar to the past with desktop applications. Developers needed to structure applications carefully to reuse components, often using DLLs or source code. Third-party applications were integrated through specific pipelines, which was inefficient. Microsoft's COM technology improved this situation by allowing developers to create and reuse components in various programming environments without sharing source code. This helped end the era of monolithic applications. Even though many applications still appear monolithic, much of their functionality is now delegated to separate components, making code easier to debug, alter, and extend.Web services are a key part of the .NET Framework, but there is still confusion about their purpose and use. This chapter explains web services and their role in Microsoft's vision of the programmable Web. It also discusses the technical standards that allow web services to function, such as WSDL and SOAP. To understand web services, it's important to recognize the limitations of current distributed application architecture. Many internet applications are "monolithic," combining various services behind a single user interface. While this model is successful, it has several drawbacks. Monolithic applications are time-consuming and resource-intensive to create, often tied to specific platforms or technologies. They are difficult to extend and enhance. Integrating multiple applications is a complex task, often requiring custom work. Reusing application logic between different applications is also challenging, especially when the applications are from different companies or use different programming languages. The situation is similar to the past with desktop applications. Developers needed to structure applications carefully to reuse components, often using DLLs or source code. Third-party applications were integrated through specific pipelines, which was inefficient. Microsoft's COM technology improved this situation by allowing developers to create and reuse components in various programming environments without sharing source code. This helped end the era of monolithic applications. Even though many applications still appear monolithic, much of their functionality is now delegated to separate components, making code easier to debug, alter, and extend.