QA:Quality Assurance-> Verifying and Validating Software Development Process. QA engineers involove in this process.QC: Quality Control-> Measureing and Monitoring Software Development Process. Higer officials like Managers involove. Monitoring means how much development done and how much development yet to done.

Quality Assurance:Process oriented testing,Clears the defects.
Quality Control:Product oriented testing,Detects the defect.

QA:  Team ensure that the process of designing product is correct or not.

QC: Team is find defects in product.