Don't be surprised if your questions evoke shrugs. Very few people in organizations understand the basics of process control. Many quality practitioners and consultants make the mistake, when talking to line operators and other workers, of immediately plunging into the deep waters of "normal curves," and flow charts. Most employees don't have a statistical background, which explains why variation reduction remains a key manufacturing challenge. Before beginning a Six Sigma initiative, everyone involved in the effort should understand the basic terminology and concepts.
Pick up just about any book about process control and you will find many focus on tools and techniques. But apart from general exhortations to "define, measure, analyze, improve and control (DMAIC)," there is little substance about how these tools and techniques fit together in an integrated, common process for achieving Six Sigma.