||QA is a set of activities for ensuring quality in the processes by which products are developed.
||QC is a set of activities for ensuring quality in products. The activities focus on identifying defects in the actual products produced.
||QA aims to prevent defects with a focus on the process used to make the product. It is a proactive quality process.
||QC aims to identify (and correct) defects in the finished product. Quality control, therefore, is a reactive process.
||The goal of QA is to improve development and test processes so that defects do not arise when the product is being developed.
||The goal of QC is to identify defects after a product is developed and before it's released.
||Establish a good quality management system and the assessment of its adequacy. Periodic conformance audits of the operations of the system.
||Finding & eliminating sources of quality problems through tools & equipment so that customer's requirements are continually met.
||Prevention of quality problems through planned and systematic activities including documentation.
||The activities or techniques used to achieve and maintain the product quality, process and service.