What is a Web Service?

Web Service

Generic definition

  • Any application is accessible to other applications over the Web.

Definition of the UDDI consortium

  • Web services are self-contained, modular business applications that have open, Internet-oriented, standards-based interfaces.

Definition of the World Wide Web Consortium (W3C)

  • 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 using SOAP messages.

What is a Web Service?

  • Web Services are Classes/Methods, NOT Servlets
  • Loosely-coupled
  • Encapsulate functionality to logical entities
  • Reuse of code and functionality
  • Distributed Architecture
  • Standardized interface & established Internet protocols

Web Service Interface
Web Service Interface

Characteristics of a Web Service

  • A web service interface generally consists of a collection of operations that can be used by a client over the Internet.
  • The operations in a web service may be provided by a variety of different resources, for example, programs, objects, or databases.
  • The key characteristic of (most) web services is that they can process XML-formatted SOAP messages. An alternative is the REST approach.
  • Each web service uses its own service description to deal with the service-specific characteristics of the messages it receives. Commercial examples include Amazon, Yahoo, Google and eBay.

Remote Access

  • IP Address - Locate a Computer
  • URI - Uniform Resource Identifier
    • Locate a file in that Computer
  • Socket and Port- Binding to a Method