Web Services Choreography Description Language: Primer is a non-normative document intended to provide an easy to understand tutorial on the uses and the features of the Web Services Choreography Description Language specification.

The Web Services Choreography Description Language (WS-CDL) is an XML-based language that describes peer-to-peer collaborations of participants by defining, from a global viewpoint, their common and complementary observable behavior; where ordered message exchanges result in accomplishing a common business goal.

The Web Services specifications offer a communication bridge between the heterogeneous computational environments used to develop and host applications. The future of E-Business applications requires the ability to perform long-lived, peer-to-peer collaborations between the participating services, within or across the trusted domains of an organization.

The Web Services Choreography specification is targeted for composing interoperable, peer-to-peer collaborations between any type of participant regardless of the supporting platform or programming model used by the implementation of the hosting environment.

It's purpose is to provide an information model that describes the data and the relationships between them that is needed to define a choreography that describes the sequence and conditions in which the data exchanged between two or more participants in order to meet some useful purpose.

As the momentum around Web Services grows, the need for effective mechanisms to co-ordinate the interactions among Web Services and their users becomes more pressing. The Web Services Choreography Working Group has been tasked with the development of such a mechanism in an interoperable way.

This document describes a set of requirements for Web Services choreography based around a set of representative use cases, as well as general requirements for interaction among Web Services. This document is intended to be consistent with other efforts within the W3C Web Services Activity.