Quality Assurance Vs Quality Control

 Quality assurance is typically focused on adherence to proper processes, in order to provide confidence that the appropriate levels of quality will be achieved. 

The use of root cause analysis to detect and remove the causes of defects, along with the proper application of the findings of retrospective meetings to improve processes, are important for effective quality assurance.

The output of quality control activities are input to quality assurance activities.Audit is an example of QA activity which looks at whether and how the process is being followed. This is preventive activity.

Quality control involves various activities, including test activities, that support the achievement of appropriate levels of quality. Test activities are part of the overall software development or maintenance process.  Testing and reviews are example of quality control activities. This is detective activity.