What do we really know about Apple's CEO? Our biography of Tim Cook outlines the person running Apple.

Tim Cook is Apple’s CEO (Chief Operating Officer). He became Apple CEO in place of Steve Jobs on 25 August 2011. Cook had previously held the role of Interim CEO during 2004, when Jobs underwent treatment for pancreatic cancer, and again during 2009 when Jobs took time off from Apple.

Cook was born on 1 November 1960, and raised in Robertsdale, Alabama (near Mobile). His father was a shipyard worker and his mother a homemaker. Cook graduated from Robertsdale High School and earned a degree in industrial engineering from Auburn University, and an MBA from Duke University.

Tim Cook

Tim Cook before Apple

Prior to taking the helm of Apple, Tim Cook was Apple’s COO (Chief Operating Officer) where he was responsible for Apple’s worldwide sales and operations. Cook joined Apple in 1998 as vice-president of operations, and steadily rose through the ranks. Before joining Apple he worked at Compaq, IBM and Intelligent Electronics.

See: Apple CEO Tim Cook sends first tweet to celebrate iPhone 5s, iPhone 5c launch

Cook had a harrowing misdiagnosis of multiple sclerosis in 1996 which compelled him to "see the world in a different way", according to an interview with his alma mater’s magazine.

Cook told an audience at D10 that Jobs struck him as someone unaffected by money, a trait that he admired. He was also said to be drawn to the loyalty of its customer base. Apple customers would get mad at Apple, but still buy their products. "An Apple customer was a unique breed," said Cook.

See: Tim Cook at D10

“Working at Apple was never in any plan that I'd outlined for myself, but was without a doubt the best decision that I ever made,” Cook told the Auburn University graduating class in his 2010 commencement speech. "Only a few months before I accepted the job at Apple, Michael Dell, the founder and CEO of Dell Computer, was publicly asked what he would do to fix Apple, and he responded, 'I'd shut it down and give the money back to the shareholders'...

"So Apple was in a very different place than it is today. And my employer at the time, Compaq Computer, was the largest personal computer company in the world. Any purely rational consideration of cost and benefits lined up in Compaq’s favour, and the people who knew me best advised me to stay at Compaq. One CEO I consulted felt so strongly about it he told me I would be a fool to leave Compaq for Apple.

"There are times in our lives when the careful consideration of cost and benefits just doesn't seem like the right way to make a decision. I've discovered it's in facing life's most important decisions that intuition seems the most indispensable to getting it right."

Watch: Full video of Tim Cook's D11 interview

Tim Cook: the man who makes Apple work

Tim Cook is credited with reinventing Apple’s approach to inventory, reducing Apple’s stock levels from months to mere days. In 2012 the analyst firm Gartner reported that Apple turns over its entire inventory every five days. The report noted that only McDonald's turns over its inventory faster. Cook is quoted as saying: "You kind of want to manage it like you're in the dairy business. If it gets past its freshness date, you have a problem."

It is largely thanks to Cook that Apple is able to bring new products swiftly and decisively to market. Cook, along with Steve Jobs and other key Apple members, is credited with rescuing Apple from the brink of bankruptcy and making it one of the most profitable, and valuable, brands on earth.

Cook is known for his work ethic and detail-oriented mind. Wired once described Tim Cook as "a quiet, soft-spoken, low-key executive," and "the yin to Jobs's yang". But some analysts have questioned his ability to drive innovation.

"Tim Cook’s the guy who makes the trains run on time,” said Roger Kay of Endpoint Technology Associates in a 2009 interview. "He’s not the creative genius… Even though in some sense he is an excellent manager and is the backstop for Steve … that’s not going to do anything except make the trains run on time. That’s not going to decide what the train should look like in five years.”

See: Former Apple executive blasts CEO Tim Cook in interview

In the year following Tim Cook’s appointment as CEO, Apple's stock price went from $376.25 to a record high of $702.10 on 19 September 2012 . Since then it has receded somewhat to its current price of $544.46 on 19 December 2013.

See: Tim Cook in a letter to employees: 'Apple has never been stronger, I'm extremely proud'

Tim Cook: the man behind Apple

Cook has kept his private life out of the spotlight, offering the press and public no details about his personal relationships. Cook recently made a rare public speech at the UN, where he spoke candidly about witnessing discrimination growing up in Alabama, in particular a cross burning in his youth - an event he said "changed him forever".

Tim Cook has offered his support for ENDA (Employment Non Discrimination Act). This act, proposed by the United States Congress, aims to prohibit discrimination in hiring and employment based upon the sexual orientation or gender identity by employers with at least 15 employees.

Cook has never addressed rumours regarding his own sexual orientation but has made it clear that both he, and Apple, support equality in the workplace. Out magazine awarded him the number-one spot of the most influential LGBT people in 2013. Cook advised people at the UN to support the rights enshrined by ENDA saying: "Do not do them because they are economically sound - although they are - do them because they are right and just."

As of 2012, Cook's total compensation package of $378m makes him the highest paid CEO in the world.