This document provides an overview of web services including:
- The architecture of web services involving service providers, requestors, and registries.
- How web services work using a request-response pattern with XML messages and WSDL descriptions.
- The main types of web services: SOAP and REST.
- Advantages like exposing business functions over the internet and interoperability.
- Disadvantages such as lack of callbacks, transactions, availability, and security issues.