Definition
QC is a set of activities for ensuring quality in products. The activities focus on identifying defects in the actual products produced.
Focus on
QC aims to identify (and correct) defects in the finished product. Quality control, therefore, is a reactive process.
Goal
The goal of QC is to identify defects after a product is developed and before it's released.
How
Finding & eliminating sources of quality problems through tools & equipment so that customer's requirements are continually met.