After 15 years at the top, Tim Cook's time as Apple's CEO is coming to an end. When Cook succeeded Steve Jobs in 2011, Apple was worth roughly $350 billion . Today, the company is worth around $4.7 trillion more than 13 times it's value when he took over. That's an extraordinary transformation. But Cook's legacy isn't simply about making Apple bigger. Cook built a different Apple Job's was known for creating products that changed consumer technology. Cook's strength was different. He turned Apple's enormous product ecosystem into an increasingly efficient global business while expanding areas such as services, wearables and Apple Silicon . Apple also returned enormous amounts of capital to shareholders through buybacks and dividends during his tenure. The result was a company that became significantly more valuable without needing to reinvent the iPhone every year. Now comes the difficult part On September 1 , John Ternus will officia...