Teams are differentiated from their environments as a system. The particularity about teams is that they have two environments which they must consider if they wish to last – the organisation and the members of the team (if you are not yet familiar with the distinction between system/environment, please first read more about it here).
Without members there is no team. As trivial as this sentence seems to be, there is something to it. This is because no team can ‘only’ focus on a task, but must also, at all times, consider the personal interests of the members, their motivating and demotivating relationships with each other and their psychodynamic patterns in the processing of relationships and needs. For a team to work well, it therefore requires the ability to encourage its members to remain engaged in the team. To build up and develop this ability is one (!) purpose of team development, because the team management alone (without team members), can never provide this competence.