According to Wikipedia, a Team is a group of people linked in a common purpose.  Of course, simply amassing individual people into a group, does not necessarily make a team.  Instead, a true team incorporates the variety of strengths (and weaknesses) of the individual members, creating a synergy that helps the individuals reach their common purpose more efficiently and with greater creativity than would have been possible through individual efforts alone.  A good team amplifies the strengths of its individuals, while minimizing their weaknesses.