QA and QC are important concepts in the quality management system, and they are different in scope, methods, concerns and purposes.

1. Different ranges

QA not only pays attention to product quality, but also pays attention to quality assurance activities throughout the product life cycle. QC mainly focuses on product quality control and quality inspection.

2. Different methods

QA adopts preventive quality assurance method to ensure the stability and reliability of products or services by formulating and implementing quality assurance plans. QC adopts inspection quality control method to ensure that the product quality meets the specified requirements through inspection, testing and audit of products or services.

3. Different concerns

QA focuses on quality assurance activities in the whole product life cycle to ensure the stability and reliability of product or service quality. QC focuses on product quality control and quality inspection to ensure that the product quality meets the specified requirements.

4. Different purposes

The purpose of quality assurance is to improve the quality and reliability of products, and to ensure that products or services meet the specified requirements in the whole life cycle by formulating and implementing quality assurance plans. The purpose of quality control is to ensure that the product quality meets the specified requirements, and to control the product quality through inspection, testing and audit.