REST stands for Representational State Transfer where as SOAP stands for Simple Object Access Protocol. SOAP defines its own security where as REST inherits security from underlying transport. SOAP does not support error handling but REST has built-in error handling. REST is lightweight and does not require XML parsing. SOAP webservices are based on a specific contract (wsdl document). REST webservices are based on resources and there isn't a specific contract between provider and consumer of the service.