To understand how teams deliver extra performance, we need to distinguish between teams and working groups. A working group's performance is made up of the individual results of all its individual members. A team's performance is made up of both individual results and collective results. Teams produce work products/results though the joint contributions of team members. This is what makes the team's collective performance greater than the sum of all individual members’ best performance. In short, a team is more than the sum of its parts.