QC-> Quality Control. 

It emphasis Quality of whole Application. 
It is a Advance of Quality Assurance.


QA-> Quality Assurance.

It emphasis Quality of Module within an Application.

qc:Quality Control is something which a testengg will do .
that is hte actual testing of the complete appln.(something 
like Validation)
qa:Quality Assuarance is the process of verifying whether 
the process followed to test the appln is correct or not.
(Vefication)

Quality Assurance makes sure you are doing the right things,
the right way.

Quality Control makes sure the results of what you've done
are what you expected.

QA means quality assurance.objective of QA is defect prevention
QC means quality control.objective of QC is defect detection

QA :Monitoring and measuring the strength of developement 
process is calles quality assurence.

QC :  The validation of the product is called quality 
control

Quality assurance is futuristic word to get the assurance 
of the quality and where as quality control is having a 
check on the quality assurance.

QUALITY CONTROL measures the quality of a product
QUALITY ASSURANCE measures the quality of processes used to 
create a quality product