A team is a group of people who have a certain task to complete. In order to meet their target, the members of the group must work well with each other.
Successful team - a group of people who tend to meet their target despite barriers. The group members cooperate with each other and take other members' ideas into consideration.
Unsuccessful team - a group of people who have a very difficult time when attempting to complete a certain task. This may be because the members of the group think of only themselves and create an uncomfortable environment for other members of the team.