# Physical contract

The concrete portion of a WSDL contract that defines the bindings and transport details used by the services defined by that contract. The physical contract answers questions such as:

* How is message traffic formatted on the wire?
* How and where does message traffic travel?
* Is there more than one option for transmitting a request?

WSDL elements used in the physical contract include: binding element, service element, operation element, and port element.