All people have roles which are both obvious and non-obvious.  One role that is immediately obvious is a workers position in the company, whether he or she is a manager or not, a team leader or not, the duties that person carries out as part of his or her job, etc.  Likewise, within a family or outside work, people have roles which are obvious, such as spouse or partner, child, parent, even friend.  However, everyone also holds roles which are not immediately obvious.  For instance, it may be that an employee is the organizer for a charity drive or walk-a-thon in the organization, or that he or she is the captain of the office softball team.  Within a family or non-work context, people also have roles which are not necessarily tied to their position.  Some people might spend time in volunteer work or leading Scout troops, etc. 

Another interesting point about roles is that the issues surrounding roles held by people have been researched by psychologists, sociologists, and other social scientists.  Most research has indicated that roles are extremely important to a persons identity.  That is, people tend to experience a greater sense of self when holding well-defined roles.  Also, research is clear on the idea that one persons roles are defined, in part, by the roles held by those around them.  These ideas are central to issues of balancing ones work roles and non-work roles.  For more on the theory of roles, see Biddle & Thomass Role Theory: Concepts and Research, published in 1966.