Enterprise WSDL

• Strongly typed, the object and its attributes are fixed.
• Contains the metadata about all standard and custom fields and objects.
• Can only be used against your Salesforce instance.

Partner WSDL

• Is loosely typed, the object and its attributes can be variable.
• Does not contain metadata about objects and fields. Takes an array of key-value pairs.
• Can be used against many Salesforce.com organizations.
• Partner WSDL is more flexibile than enterprise WSDL. Methods use sObject superclass rather than specific classes. Application handles fields as arrays of name-value pairs.

Enterprise WSDL Example:

Position__c p = new Position__c();
p.setName("Test");

Partner WSDL Example:

sObject p = new sObject();
p.setType("Position__c");
p.setField("Name", "Test");