Web Services Overview

Web Service Definition:

A Web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards. 

Standard web services technologies:

SOAP : Simple Object Access Protocol (SOAP) is an XML-based protocol used for exchanging information in a decentralized and distributed environment using XML, is a standard developed by the W3C.SOAP defines the protocol by which web services can be invoked.It can be used over any transport protocol layer such as HTTP, SMTP. SOAP defines the basic structure of messages and encoding rules for data types (used as parameters in procedure/method calls) and the encoding of procedure calls and responses. SOAP also defines bindings to specific transport protocols most notably to HTTP and SMTP.

WSDL: WSDL stands for Web Service Description Language.
  • Describes how the service is to be used
  • Compare (for example) to Java Interface.
  • Guideline for constructing SOAP messages.
  • WSDL is an XML language for writing Application Programmer Interfaces (APIs).
UDDI: The publication and discovery layer provides the mechanisms for the service brokers. This layer is based on the Universal Description, Discovery and Integration (UDDI) standard, a standard that defines XML-based service AND business descriptions, and a SOAP-based standard API to interact with the service broker.

We have explained Web Services Implementation and brief description about  Web Services Architecture in next articles