A new book by Yukari Iwatani Kane called Haunted Empire: Apple After Steve Jobs will be published on March 18 by HarperBusiness. The book describes Cook's early life as a student, his business pedigree, and his early years at Apple.

Cook started at IBM with a degree from Auburn University in industrial engineering, later getting an MBA from Duke. He later moved to Compaq and from there was invited to join Apple.

The book talks about his discipline and focus: "To some, Cook was a machine; to others, he was riveting. He could strike terror in the hearts of his subordinates, but he could also motivate them to toil from dawn to midnight for just a word of praise."

"Meetings with Cook could be terrifying. He exuded a Zenlike calm and didn't waste words. 'Talk about your numbers. Put your spreadsheet up,' he'd say as he nursed a Mountain Dew."

The book also details Cook's management style since becoming CEO. Notable examples include how the Apple chief is changing the company's work climate through initiatives such as charity programs. He also works on being more sociable and open to employees than Jobs despite his high expectations.

"Cook also knew the power of silence," the book continues. "He could do more with a pause than Jobs ever could with an epithet. When someone was unable to answer a question, Cook would sit without a word while people stared at the table and shifted in their seats. The silence would be so intense and uncomfortable that everyone in the room wanted to back away. Unperturbed, Cook didn't move a finger as he focused his eyes on his squirming target. Sometimes he would take an energy bar from his pocket while he waited for an answer, and the hush would be broken only by the crackling of the wrapper."

Cook sent his first email as CEO to employees in August 2011, a few months before Jobs died.

"I want you to be confident that Apple is not going to change," he wrote. "Steve built a company and culture that is unlike any other in the world and we are going to stay true to that-it is in our DNA. I am confident our best years lie ahead of us and that together we will continue to make Apple the magical place that it is."

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