Today's switch-mode power converters are extraordinary devices converting power with efficiencies approaching 100% and power conversion densities into the 100's of watts per cubic inch. Just how do they do that? This seminar is a look "under the hood" of switch mode power converter. Imagine looking under the hood of a car at the engine with a mechanic. The mechanic would describe all of the various parts, like pistons and fuel injectors, and how they work together to create the power to drive the car. This seminar is a "look under the hood" of switch mode power converters. The goal is to present the principles and concepts needed to understand how switch mode converters work without a deep technical dive into the details. The first half of the seminar will focus on the circuits ("topologies") used to convert power. The various building blocks, such a switching devices and inductors will be described. Then the key principle of switch mode power will be presented to show how an ideal switch mode converter can convert at 100% efficiency. This introduces the buck converter which is explored in some detail. The workings of other key topologies such as the boost, buck-boost, and flyback converter are shown to expand the understanding. In the second half, the basics of controlling a switch mode power converter are explained. A quick review of systems and feedback starts the discussion. Then roles and function of the error amplifier, compensator, and modulator described. The concepts of how one designs a stable control are also discussed. The seminar concludes with an overview of current mode control. This seminar is suited for those wishing to know how a switch mode power converter works without being drenched in technical details, such as those new to switch mode power conversion or those working in sales, marketing, or application support of switch power converters or components used in switch mode power converters.