What is a primary distinction between SOAP and REST?

The primary distinction between SOAP and REST lies in their approach to web services and data transmission. SOAP, or Simple Object Access Protocol, is a protocol that is designed for exchanging structured information in the implementation of web services. Its focus is on operations or actions that can be performed, which are defined in its WSDL (Web Services Description Language) document. This emphasis on operations supports complex operations and transactional actions.

In contrast, REST, or Representational State Transfer, is an architectural style that emphasizes resources, which are identified by URLs. REST uses standard HTTP methods (GET, POST, PUT, DELETE, etc.) to operate on these resources, allowing for a more straightforward and web-centric approach to interaction. This resource-focused methodology makes REST adaptable not only to the web but also to a wider variety of clients and devices.

The incorrect options reflect misunderstandings regarding the characteristics and functionalities of SOAP and REST. For instance, describing SOAP as lighter than REST underestimates the overhead associated with the XML-based messages and established protocols that SOAP uses. The statement that REST supports SSL only is inaccurate because both SOAP and REST can use SSL for secure transactions. Lastly, asserting that REST requires XML format is not correct, as REST can utilize multiple formats, including JSON, XML