In context: In the eight years since he replaced co-founder Steve Jobs as the head of the firm, Tim Cook has helped Apple briefly become the world’s first public company to be worth $1 trillion while tripling its annual revenue. So, it’s not surprising that the man being groomed as his successor is closer to the softly spoken CEO than firebrand Jobs.

Following the sudden and unexpected departure of Chief Design Officer Jony Ive, the iPhone maker’s Chief Operating Office, Jeff Williams, took over Apple’s design studio. Bloomberg took an in-depth look at the man it calls the "second-most important person at Apple and Tim Cook's heir apparent as CEO.”

According to current and former employees speaking on the condition of anonymity, Williams is described as “a modest, disciplined, demanding leader in the current CEO’s style,” who handles negotiations with suppliers and is a "bit more hands-on with product development than Cook." He’s in charge of both the Apple Watch team and the company’s entire global supply chain, and oversees the development of all Apple hardware.

Jobs was famous for his fiery temper and public outbursts, but Williams, who is regarded as the first choice should Cook leave, shares many similarities with the current CEO, including age, education (MBAs from Duke University), growing up in the American south, and having worked at IBM before coming to Apple. Cook was also COO before taking the top job.

One executive said that Williams tries to use the same language as engineers in his conversations, "though he can be self-deprecating about his technical expertise."

"The COO, also like his boss, has a knack for watching, listening, and asking sharp questions," writes Bloomberg.

While Williams may be the perfect replacement for Cook, it could be many years before the current CEO decides to leave his position. But if there was ever an emergency, Apple will be happy in the knowledge that it has a perfect replacement.

Speaking about Williams, a former Apple executive said: “He’s the closest thing at the company to Tim Cook, and you’ll get more of that. If you think Cook is doing a good job, then it’s a good choice.”