It's been a decade since Tim Cook became the CEO of Apple. Here's how his leadership has changed the world.

• When Tim Cook became the CEO of Apple in 2011, many wondered if he could fill Steve Job's shoes.
• Over the past decade, Apple became the first company worth $2 trillion.
• Cook said he trusted his instincts to get to Apple, and they continue to guide him as a leader.

In his 2010 commencement speech at Auburn University, then-Apple Chief Operating Officer Tim Cook shared the "most significant discovery" that he made when he came to Apple in 1998 - trusting his intuition.

"I had to think beyond my training as an engineer - engineers are taught to make decisions analytically and largely without emotion," Cook said during the speech. "There are times in all of our lives when a reliance on gut or intuition just seems more appropriate - when a particular course of action just feels right.

"And increasingly, I've discovered it's in facing life's most important decisions that intuition seems the most indispensable to getting it right."

August 24 marks the 10th anniversary of Cook taking the helm of Apple. Before then, he was Apple's chief operating officer from 2005 to 2011. Cook became CEO when Steve Jobs stepped down in 2011. Jobs died six weeks later. And after a decade, Cook's instinctive choices have made Apple one of the most important companies of the modern age. And last year, the tech giant became the first company to hit a $2 trillion market cap.

When Jobs stepped down, some critics questioned Cook's ability to deliver the same level of creativity and innovation, but Cook found new ways to make Apple products irresistible.

As a tech leader, Cook went up against the National Center for Public Policy Research, telling the conservative group of climate-change deniers with Apple investments to "get out of this stock." In 2017, He defended young immigrants when the Trump administration tried to end the Deferred Action for Childhood Arrivals program. Under his leadership, Apple has increased its charitable donations, including a $100 million investment in racial-justice initiatives in January.

When he was the chief operating officer of Apple, Cook was known as the quiet, hardworking Southern gentleman, in contrast to Jobs' reputation of having an abrasive personality. But over the past 10 years, Cook has demonstrated keen instincts, some of which he credits to his predecessor. Jobs often made choices that reflected sharp intuition, like scrapping the plastic screen on the iPhone for glass just a few months before the launch.

Cook's support of social issues as a business leader has also become a characteristic of his leadership style. In 2014, he became the first openly gay CEO of a Fortune 500 company.

Interviewers often ask Cook whether corporate leaders should take a stance on public policy, and his willingness to go against the grain where other business executives remain silent could be the greatest part of his legacy.

"Apple is about changing the world," Cook said at Fortune's CEO Initiative in 2018. "It became clear to me some number of years ago that you don't do that by staying quiet on things that matter."