Privilege, as it applies to a team, is a slightly different kind of power from either rank or roles. Privilege is a kind of inherited power, a sort of sweat equity built up over time that a particular kind of team member enjoys the benefits of, even if he or she did little or nothing to create it.
One of the most obvious examples of privilege is race & gender. For example, I am a white male. On top of that, I'm a tall white male. All of these are simple facts of my existence that I had no part in creating for myself. I did not work for them. They simply are. And yet, because I am a tall, white male, I enjoy a certain level of privilege on most teams I am a part of. I'm given a certain amount of deference and respect that I would not receive if I were something other than tall, white and male.
Clearly, as this example illustrates, not all forms of privilege are necessarily good or desirable. But other forms of privilege are less ethically dubious. Seniority, for example. The person who has been on the team the longest generally carries a sort of privileged status. He or she may have freedoms to say or do things that newer members of the team do not. Or, what if you happen to become good friends with the boss? You start to do stuff together outside of work. Now you are in a place of privilege, and you will notice that the rest of the team will begin treating you differently. Some will defer to you more; others will distance themselves from you. That's privilege at work.
Though it is a kind of authority, privilege is not quite the same as rank. Rank refers to a direct authority you have within the team. Privilege speaks more to the notion of authority by association. Privilege is more about cultural status than personal power or ability. I may, for example, be a very ineffectual team member with little rank in any arena, but because I am a tall, white male, I will nonetheless continue to enjoy the privileges associated with that cultural status. People may tolerate my ineptness much longer, for example, than they might someone who wasn't a tall, white male, before kicking me off the team.
I like Andy Crouch's definition of privilege. He describes it as "the continuing benefits of past successful exercises of power." White males have dominated the power structures in our society for hundreds of years. Though that dynamic is finally beginning to change (thank God!), I still experience the continuing benefits of our white-male-dominated past. That's privilege.
What kind of privilege is most prevalent on your team?