Salesforce provides two SOAP API WSDLs for two different use cases.
The enterprise WSDL
- optimized for a single Salesforce org.
- It’s strongly typed.
- it reflects your org’s specific configuration, meaning that two enterprise WSDL files generated from two different orgs contain different information.
- whenever you make a metadata change to your org, regenerate the WSDL file
The partner WSDL
- optimized for use with many Salesforce orgs.
- It’s loosely typed.
- It doesn’t change based on an org’s specific configuration.
Typically, if you’re writing an integration for a single Salesforce org, use the enterprise WSDL. For several orgs, use the partner WSDL.