What is the difference between QA and QC?

Quality Assurance/Quality Control 
Quality Assurance is a focus on processes 
like defining,deploying ,continuous improving  
with the goal of defect prevention. 
 
Quality Control is a focus on products 
defect/bug detection with the goal of defect detection 

QA assurance people focus on the process by conducting reviews, meetings, walkthroughs using check lists and issue lists. 
QA is a preventive action. 
QC people focusses on the product by coducting the inspections and audits. 
QC is corrective action.

Actual testing = Quality Control of a project 
 
Quality Control = Processes used to test the Project Functionality 
 
Quality Assurance = Measures the quality of QC processes used to create a Quality Project.

Quality Assurance: A set of activities designed to ensure that the development and/or maintenance process is adequate to ensure a system will meet its objectives.

Quality Control: A set of activities designed to evaluate a developed work product.

Testing: The process of executing a system with the intent of finding defects. (Note that the "process of executing a system" includes test planning prior to the execution of the test cases.)

Quality Assurance:
1. Quality assurance meant for developing, organizing the
best quality process
2. QA is process related
3. QA focuses on building in quality and hence preventing
defects
4. QA: Deals with process
5. QA: for entire life cycle
6. Quality Assurance makes sure you are doing the right
things, the right way.
7. QA is preventive process.

Quality Control:
1. Quality control meant for implementing the process
developed by former team
2. QC is the actual testing of the software
3. QC focuses on testing for quality and hence detecting
defects
4. QC: Deals with product
5. QC: for testing part in SDLC
6. Quality Control makes sure the results of what you've
done are what you expected
7. QC is corrective process.