In simplest terms, a Web service is an application. That is, a Web service provides a defined set of functionality to achieve a specific end, for example, a mapping service that takes two addresses and tells you how to travel between them. Before the adoption of the Internet, a client could only use an application if it was installed on a local machine. Today, with the emergence of the Java™ 2 platform and Internet standards such as the HyperText Transfer Protocol (HTTP), eXtensible Markup Language (XML), Remote Procedure Call (RPC), Web Services Descrip-tion Language (WSDL), and Simple Object Access Protocol (SOAP), it is possible to access an application on any computer, anywhere in the world.

The promise of Web services is to put any application — regardless of the platform on which it is developed or the architecture on which it is deployed — within the reach of any client. It seeks to create an environment where any networked client, running on any type of device, can find a service on the network and use it as though it was a local service.

Today, building and deploying applications on the Internet is a multibillion dollar industry. In this dynamic environment, Web services give companies an unprecedented opportunity to make use of the functionality and services provided by others. From airline Web sites that offer car rental and hotel services with up-to-the-minute rates, to the doctor who has access to online medical services from his or her cell phone, Web services are becoming a part of daily life. This paper provides a brief overview of the field of Web services and then looks at how the Java 2 Platform, Micro Edition (J2ME™) Web Services Specification fits into the picture.