Strictly speaking, SOAP and REST aren’t directly comparable: REST is an architectural style, and SOAP is a specific protocol defined by a standard. PayPal, for instance, exposed a SOAP API to its services soon after its 2002 acquisition by eBay. A REST-based implementation is simple compared to SOAP. This is not always practical particularly when you have many platform and language combinations or when you want to offer services to anonymous clients over the internet.
SOAP (Simple Object Access Protocol), was created in 1998 by Dave Winer et al in collaboration with Microsoft. This document has been produced by the XML Protocol Working Group , which is part of the Web Services Activity It has been reviewed by W3C Members and other interested parties, and has been endorsed by the Director as a W3C Recommendation.
What’s more, only one client can use the services of one server in typical situations. If it is written in java then all you would need to do (conceptually) in the SOAP-based solution is include the business logic as a Jar between the Service Method Jar and the JDBC Jar in the above diagram.
It uses XML information set for the format of its messages. The Magento SOAP API v2 does not support the call() and multiCall() methods, and instead provides a separate method for each API resource. Server can be a http Server or express framework based server wsdl is an xml string that defines the service.
SOAP is a standard for encoding messages in XML that invoke functions in other applications. Here is how you can invoke a web service via database-stored procedures – and in explaining so, I’ll address the differences of REST vs. SOAP. Authentication is crucial to this API; moreover, much of the API realizes business transactions as two-phase commits, rather than just data look-ups or simple-minded updates.