Six Sigma is a data-driven methodology aimed at improving the quality of processes by identifying and removing the causes of defects. It utilizes statistical tools and techniques to analyze and enhance operational performance, ultimately leading to increased efficiency and customer satisfaction. The term 'Six Sigma' refers to a statistical measure that indicates how much a process deviates from perfection. By striving for a level of quality where only 3.4 defects occur per million opportunities, organizations can achieve significant improvements in their processes and products, fostering a culture of continuous improvement.