From http://www.w3schools.com (Copyright Refsnes Data)
SOAP is a simple XML-based protocol to let applications exchange information over HTTP.
Or more simply: SOAP is a protocol for accessing a Web Service.
SOAP stands for Simple Object Access Protocol, and is a format for sending messages.
To learn more about SOAP, read our SOAP tutorial.
SOAP 1.1 was suggested in a note to W3C in May 2000 (by Developmentor, IBM, Lotus, Microsoft, and Userland), as a protocol for exchanging information in a distributed environment.
SOAP 1.2 became a W3C Recommendation 24. June 2003.
| Specification | Draft / Proposal | Recommendation |
| SOAP 1.2 Primer | 24. Jun 2003 | |
| SOAP 1.2 Primer SE | 27. Apr 2007 | |
| SOAP 1.2 Messaging | 24. Jun 2003 | |
| SOAP 1.2 Messaging SE | 27. Apr 2007 | |
| SOAP 1.2 Adjuncts | 24. Jun 2003 | |
| SOAP 1.2 Adjuncts SE | 27. Apr 2007 | |
| SOAP 1.2 Test Collection | 24. Jun 2003 | |
| SOAP 1.2 Test Collection SE | 27. Apr 2007 | |
| SOAP 1.2 Attachments | 08. Jun 2004 | |
| SOAP 1.2 Email Bindings | 03. Jul 2002 | |
| SOAP 1.2 Normalization | 08. Oct 2003 | |
| SOAP 1.2 Serialization | 08. Jun 2004 | |
| Web Services Addressing 1.0 - Core | 09. May 2006 | |
| Web Services Addressing 1.0 - SOAP | 09. May 2006 |
From http://www.w3schools.com (Copyright Refsnes Data)