Commercial/Privatized Space Travel

How does Science, Technology, Engineering, and Math apply to commercial/privatized space flight?
Provide an in depth look at the major leaders in privatized space exploration (Blue Origin Jeff Bezos, SpaceX Elon Musk, Virgin Galactic Richard Branson, and government funded NASA).
How are these industries are revolutionizing how we get to space; the engineering, cost, different technologies, and amenities provided?