Teamwork is the collaborative effort of a group to achieve a common goal or to complete a task in the most effective and efficient way. This concept is seen within the greater framework of a team, which is a group of interdependent individuals who work together towards a common goal. Basic requirements for effective teamwork are an adequate team size. The context is important, and team sizes can vary depending upon the objective. A team must include at least 2 or more members, and most teams range in size from 2 to 100. Sports teams generally have fixed sizes based upon set rules, and work teams may change in size depending upon the phase and complexity of the objective. Teams need to be able to leverage resources to be productive (i.e. playing fields or meeting spaces, scheduled times for