A team is a group of users who perform similar roles. In a small organization, this might mean that all Sales Department users are part of the Sales Team. In a larger organization, there may be Telesales, Direct Sales, and Field Sales teams.

Putting Teams to Use in Your Organization
Each user can be made a member of one team and can be given rights to view multiple teams. Communications, Opportunities, Leads, and Cases can all be tracked by individual user and by team. Also, Communications can initially be assigned to a team and later reassigned to an individual.