Web Services can be categorized into two types
SOAP Web Services
Rest Web Services
Full form is Simple Object Access Protocol
XML based message protocol
It uses WSDL for communication between consumer and providers
It supports XML-coded messages over a transport protocol such as HTTP,SMTP.
SOAP Message Structure
Representation of Sample Message:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/">
Envelope:It identifies the XML document as a SOAP message.
Header: The Header section can contain meta data about the message.
Meta data is "data that describes data". A SOAP message does not have to contain a Header.
Header elements make it possible to extend the base SOAP protocol, to accommodate needs that the
SOAP specification does not include.
Body:It is mandatory element, that contains request and response information
Fault: When a message is rejected, the server generates a Fault, or error message.
Faults are commonly caused by unrecognizable header fields, messages that cannot be authenticated, or problems that occurred when the server attempted to invoke a method or process the message.
Note: Header and Fault are optional elements.
Full form is Representational State Transfer
It is an Architectural style Protocol
It can access using Uniform Resource Identifiers(URIs)
It uses XML Or JSON to send and receive data
It mainly uses HTTP &HTTPS protocol.
client sends an HTTP request to Webserver, similarly Webserver sends an HTTP response for the same .
For communications it uses various HTTP methods as shown below: