Hi
SAP stands for Simplified Application Process. As the name implies, it is a simplified process in the terms that you donot need to send your documents at the time of making application. Just a simple plane application form will do. Later when CIC is ready to review your case you will be notified to provide documents. At that time only you will be needed to update information and provide documents.
Please see
www.cic.gov.ca for related forms and guides.
Thanks
Cool