Who Is Elon Musk?

He's the man behind Tesla Motors Inc. (Nasdaq: TSLA), SolarCity Corp. (Nasdaq: SCTY), and PayPal, but despite his fame, many still ask themselves "Who is Elon Musk?"

The quote from Musk's 2013 "TED Talks" interview gives a glimpse of the $7 billion man and what has driven him in his career.

"It goes back to when I was in University, I thought about what problems are most likely to affect the future of the world," Musk said. "I think it's extremely important that we have sustainable transport and sustainable energy production. That overall sustainable energy production is the biggest problem we have to solve this century."

That forward-thinking attitude is what has led Musk throughout his career...

Becoming an Internet Millionaire

Musk was born in South Africa in 1971 and taught himself computer programming at an early age. His "career" began at age 12 when he sold the computer code to his self-designed video game "Blastar" for $500.

After migrating to Canada at age 17, Musk attended Queen's School of Business in Ontario for two years. From there, he transferred to the University of Pennsylvania, where he earned a bachelor's degree in economics from the Wharton School. He would later earn a second bachelor's degree in physics.

Musk later abandoned his plan to earn a Ph.D. in applied physics from Stanford after just two days to start his entrepreneurial career.

That move worked out okay for Musk.

His first entrepreneurial endeavor was creating the web software company Zip2 with his brother. The company marketed web-based "city guides" and obtained contracts with several newspapers including The New York Times and The Chicago Tribune. Zip2 was eventually purchased by Compaq in 1999 for $307 million.

Following the sale of Zip2, Musk co-founded the Internet payment company X.com. After only a year, X.com merged with Confinity, which owned PayPal.

PayPal is what initially brought Musk into the public spotlight, as he worked to brand the company into a major name in the e-commerce industry. When the company was bought by eBay Inc. (Nasdaq: EBAY) for $1.5 billion in 2002, Musk walked away with $165 million.

And while Musk's past achievements are prodigious, it's the projects he's currently working on that could change the world...

The Impact of SolarCity (Nasdaq: SCTY) and SpaceX

Currently, Musk has his hands full as the co-founder of Tesla, SolarCity, and SpaceX.

SpaceX was founded in 2002 and is focused on reducing the cost of space transportation. The private company is also occupied with the human colonization of Mars. SpaceX has launched several rockets and satellites and is the first private company to send a spacecraft to the International Space Station.

Currently, SpaceX's main project is developing reusable launch vehicles for space exploration, which according to Musk would drastically cut back on space transportation costs.

As the co-founder of SolarCity, Musk is also attempting to increase the popularity and efficiency of solar power at the residential level.

The company was founded in 2006 and has brought its technology to 14 states. The company accounted for 32% of the residential solar market in the United States in the third quarter of 2013, up from 26% the previous quarter.

Like every endeavor Musk seems to take on, SolarCity is booming. Its revenue was reported as $47.3 million in Q4 2013, up 87% year over year. Shares of SCTY stock are up nearly 400% in the last 12 months.

But none of Musk's undertakings have taken off quite like Tesla...