1.) SOAP relies exclusively on XML to provide messaging services.
2.) SOAP has some rigid set of messaging patterns than REST.
The rules in SOAP are important because without these rules,
you can’t achieve any level of standardization.
3.) SOAP is designed to support expansion, so it has all sorts of other acronyms and abbreviations associated with it, such as WS-Addressing, WS-Policy, WS-Security, WS-Federation, WS-ReliableMessaging, WS-Coordination, WS-AtomicTransaction, and WS-RemotePortlets.
The various components of SOAP protocol are,
1. SOAP Envelope
It is the root element in the SOAP message. It has an optional Header element and a mandatory Body element.
2. SOAP Header
It is an optional element which is used to pass the application specific information like Authentication information etc.
3. SOAP Body
It is the mandatory element which carries the data between the Client and the Server machines.
4. SOAP Fault
This is used to carry the Error information in the SOAP message
SOAP stands for Simple Object Access Protocol. It is an XML based protocol by which applications can exchange information in the form of XML over HTTP interface.Web Services uses SOAP for sending and receiving the messages between different applications.
Web Service provides the standard for communication between different software applications that are running in different platform. For example, an application developed using the language “C++” in Windows can communicate with another application developed using “Java” in Linux.By this way, any applications can communicate with other application provided they follow the standards defined by Web Service.