Difference between Quality Control and Quality Assurance?

	Quality Control	Quality Assurance
Definition	QC is about checking at the end of some development process (e.g. - a design activity) that we have built quality in i.e. that we have achieved the required quality with our methods.	QA is about having an overall development and management process that provides right environment for ensuring quality of final product.
Description	QC is like testing a module against requirement specification or design document, measuring response time, throughput etc.	QA gives us added assurance that the whole producing or checking process is properly planned and executed and thus maintaining high quality.
What it does	To check that the modern methods of software development are largely designed to ensure right quality is achieved. QC checks that these methods are in place and to discover where they are not then corrections are to be made.	It gives us added assurance that the while producing / checking process is being properly planned and executed and hence is keeping high our chances of producing software of required quality.
Stages	Define features and levels Define feature check procedure Carrying out the check procedure Record the result take and record any corrective action taken.	1. Determination of quality policy through Quality Management System 2. Checking that predetermined Quality control activities are being properly taken care off.
Best carried out on	QC is best carried out on products	QA is best carried out on process.
Phase of implementation	QC should take place at every stage of SDLC.	QA should be done at end of every SDLC i.e. when product building is complete.
Technique	Structured walkthrough, Fagan Techniques are some of QC techniques.	Quality policy defined and generally implemented in the form of Quality Management System is used to carry out QA.