What are the differences between Six Sigma and Lean Principles?

BSOP 588 Managing Quality
Week 6
DQ 1) Six Sigma and Lean Principles
What are the differences between Six Sigma and Lean Principles? What effect does upper management commitment have on the success of either of these processes?
DQ 2) Applying Lean and Six Sigma Principles
Identify some of the key processes that need improvement in your organization associated with the following: sale, marketing, customer service, supply chain management, human resources, manufacturing, etc. What types of Lean Principles and/or Six Sigma initiatives could you use to rectify these problems? Explain why you think they would work best