For most companies, the chief executive serves as a quarterback, ensuring the plays are run correctly, while the chairman is the coach, providing the bigger-picture view.
Or, for the geeks out there, the CEO is Luke Skywalker to the chairman's Yoda.
It's unclear what Steve Jobs' role will exactly be. The Star Wars analogy may be apt in that Jobs could dispense his sagely advice to CEO Tim Cook. Or the chairman position could be the first step to his eventual departure from the company.
The role of chairman has evolved over the past few years, particularly in the technology world. Charismatic leaders and longtime executives had long occupied the dual roles of CEO and chairman, giving them a tight rein over their companies.
But investor concern over wielding too much power has spurred many companies to divide up the roles to two people, with the CEO running the day-to-day operations and the chairman shepherding the company and looking out for the interests of the shareholders.
There are many different kinds of chairmen out there. Nike's co-founder and chairman, Phil Knight, still holds tremendous power and has engineered past changes in executive leadership., meanwhile, is essentially a figurehead who has left the direction of the company to Larry Page and Sergey Brin.
Jobs will likely fall in between those two chairmen, analysts said. Apple's founder already relinquished much of his operational responsibilities to Cook when he took his medical leave of absence in January. But his words will still carry tremendous weight in regard to the company's direction.
"Through the years he's become more of a father figure leading his team," said Sterne Agee analyst Shaw Wu.
Jobs is taking the position from William Campbell, who is also the chairman and former CEO of Intuit. Wu noted that Campbell had been the elder statesman of the company, and now Jobs is occupying that role.
Others, however, believe the chairman role has grown increasingly insignificant. Global Equities Research analyst Trip Chowdhry said the role has largely been a gracious way of moving a CEO out of the company. When Verizon Communications Chief Executive Ivan Seidenberg, he retained his chairman position as Lowell McAdam took over.
In Apple's case, Chowdhry believes Jobs has set up Apple's product roadmap for the next three years and is gracefully leaving the company.
"He's distancing himself from Apple," Chowdhry said. "I think he's already given his guidance."
The broader trend to separate the chairman role was spurred by shareholder activists and investor-advocate groups, who believe that occupying both positions could be a conflict of interest. It has resulted in a lot of directors with less direct control over the company's regular operations. Instead, they mainly deal with evaluating executive performance and whether they are acting in the best interests of the shareholders, as well as running the regular corporate board meetings.
Despite the push, many companies are still run by executives who also serve as chairman. Michael Dell continues to have tight control over the company he founded. In 2007, Dell and the board pushed out Kevin Rollins, allowing him to retake the helm.
AT&T has also chosen to remain the traditional model, withjust as his predecessor, Ed Whitacre, did.
But sometimes the decision to consolidate power up top has a backlash. Last year, Hewlett-Packard was left without a chairman or chief executive whenamid an investigation related to claims of sexual harassment. Four years earlier, Hurd had taken the unusual move of consolidating the already split roles into one position.
HP learned its lesson and in October.
Apple fortunately doesn't have the same kind of identity crisis as HP. In Jobs, it has a chairman that has strong vision of where the company is going, even if he isn't running it.
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