A binding, as defined by Web Services Description Language (WSDL), is similar to an interface, in that it defines a concrete set of operations. Each XML Web service method is an operation within a particular binding. XML Web service methods are members of either the default binding for an XML Web service or a binding specified within a System.Web.Services.WebServiceBindingAttribute applied to a class implementing an XML Web service. An XML Web service can implement multiple bindings, by applying multiple System.Web.Services.WebServiceBindingAttribute attributes to an XML Web service.

Once one or more System.Web.Services.WebServiceAttribute attributes are applied to an XML Web service, a System.Web.Services.Protocols.SoapDocumentMethodAttribute or System.Web.Services.Protocols.SoapRpcMethodAttribute can be applied to individual XML Web service methods to indicate the binding operation implemented by a particular XML Web service method. Set the System.Web.Services.Protocols.SoapDocumentMethodAttribute.Binding property of System.Web.Services.Protocols.SoapDocumentMethodAttribute or System.Web.Services.Protocols.SoapRpcMethodAttribute to specify the binding an XML Web service method is implementing an operation for.