Basically we use binding in WSDL to define format of messages and detailed information about protocol of web services.

I have given you binding consist of two attributes.

these are name attribute and type attribute(name is used to define binding name where as type is used to define binding port.

I case of SOAP binding it has two attribute. These are style and transport attribute.

Example:

<message name="getTermRequest">

<part name="term" type="xs:string"/>

</message>

<message name="getTermResponse">

<part name="value" type="xs:string"/>

</message>

<portType name="glossaryTerms">

<operation name="getTerm">

<input message="getTermRequest"/>

<output message="getTermResponse"/>

</operation>

</portType>

<binding type="glossaryTerms" name="b1">

<soap:binding style="document"

transport="http://xyzsoap.org/soap/http" />

<operation>

<soap:operation

soapAction="http://soapexample.com/getTerm"/>

<input>

<soap:body use="literal"/>

</input>

<output>

<soap:body use="literal"/>

</output>

</operation>

</binding>