SOAP (Simple Object Access Protocol)
Simple Object Access Protocol (SOAP) is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks.
It relies on Extensible Mark-up Language (XML) as its message format, and usually relies on other Application Layer protocols, most notably Hypertext Transfer Protocol (HTTP) or Simple Mail Transfer Protocol (SMTP), for message negotiation and transmission. XML was chosen as the standard message format because of its widespread use by major corporations and open source development efforts.
There are a wide variety of freely available tools that significantly ease the transition to a SOAP-based implementation. The lengthy syntax of XML has both benefits and drawbacks. XML promotes readability for humans, facilitates error detection, and avoids interoperability problems, but it can slow processing speed and can be cumbersome to work with.
As an example of what SOAP procedures can do, an application can send a SOAP message to a server that has web services enabled – such as a real-estate price database – with the parameters for a search. The server then returns an XML-formatted document with the resulting data, e.g., prices, location, features. Because the generated data comes in a standardised machine-readable format, the requesting application can then integrate it directly.