Team building is a collective term for various types of activities used to enhance social relations and define roles within teams, often involving collaborative tasks. It is distinct from team training, which is designed by a combine of business managers, learning and development/OD (Internal or external) and an HR Business Partner (if the role exists) to improve the efficiency, rather than interpersonal relations.

Many team-building exercises aim to expose and address interpersonal problems within the group.

Over time, these activities are intended to improve performance in a team-based environment. Team building is one of the foundations of organizational development that can be applied to groups such as sports teams, school classes, military units or flight crews. The formal definition of team-building includes:

• aligning around goals
• building effective working relationships
• reducing team members' role ambiguity
• finding solutions to team problems

Team building is one of the most widely used group-development activities in organizations. A common strategy is to have a "team-building retreat" or "corporate love-in," where team members try to address underlying concerns and build trust by engaging in activities that are not part of what they ordinarily do as a team.

Of all organizational activities, one study found team-development to have the strongest effect (versus financial measures) for improving organizational performance. A 2008 meta-analysis found that team-development activities, including team building and team training, improve both a team's objective performance and that team's subjective supervisory ratings. Team building can also be achieved by targeted personal self-disclosure activities.