Team sport is a type of sports competition in which a group of people act together as a unit to compete against another group. These groups are often called teams or sports leagues, and they are distinct from other types of groups in that most of the activities performed by them are stipulated and controlled by a set of rules. These rules can be very extensive, for example dictating the way in which a football team must advance the ball or restricting when a player is allowed to use hands during a soccer game. Similarly, the sports league to which a team belongs can stipulate when and how often the team can practice and play games.

In the case of American football and some other team sports, these rules can be viewed as a form of social contract that establishes the mutual benefit to players and spectators of participating in a particular game. This mutual interest can also be seen in the emergence of fan bases for certain team sports, which is a clear sign that many fans perceive participation in a particular game as part of their identity.

Besides being fun and entertaining, team sports can teach children valuable life lessons. These include the importance of working with others, respecting different opinions and putting personal differences aside for the greater good of the team. In addition, team sports provide kids with the opportunity to develop and practice problem-solving skills. They also help to improve cardiovascular health by increasing blood circulation, which can reduce the risk of heart disease.

Although some team sports are primarily individual (such as track and field and golf), there are other more team-oriented sports, such as volleyball, basketball, hockey and baseball. These teams compete against each other as a unit, and the performance of the team is measured by the cumulative scores of its members. Other sports, such as synchronized swimming and doubles tennis, also have a team element. In synchronized swimming, swimmers perform coordinated routines in tandem with other team members, and in relay races, teams compete against other teams by running segments of a race together.

Some team sports, such as ice hockey and basketball, involve contact between athletes, and the physical nature of these games invites comparisons with combat. Indeed, the occurrence of parallels between team-contact play and combat has been noted by evolutionary social scientists and biologists. Research into the nature of these parallels continues, for instance examining the behavioral and contextual cues that evoke similarities between team contact play and combat (e.g., hormone profiles associated with team contact play, and the heightened self-perceived mate value associated with victory in a sporting event). Ultimately, this body of research suggests that team-contact play may serve an important societal function by promoting healthy lifestyles through increased levels of physical activity. It can also promote feelings of camaraderie and a sense of belonging among its participants. This in turn can contribute to a sense of happiness.