SOAP services are web services that use SOAP as the standard communication protocol for XML-based message exchanges.
The standard HTTP protocol makes it easier for SOAP model to tunnel across firewalls and proxies without any modifications to the SOAP protocol.
- The Web Services Description Language (WSDL) contains and describes the common set of rules to define the messages, bindings, operations and location of the Web service. A WSDL file is a formal contract to define the interface that the Web service offers.
- SOAP services require less coding than when designing REST services. For example, transactions, security, coordination, addressing, and trust are defined by the WSDL specification. Most real-world applications are not simple and support complex operations, which require conversational state and contextual information to be maintained. Application developers do not need to worry about writing this code into the application layer themselves.
- SOAP supports several technologies, including WSDL and XSD.