CBT has been used to describe a broad range of different tourism models but usually refers to tourism that involves community participation and aims to generate benefits for local communities in the developing world by allowing tourists to visit these communities and learn about their culture and the local environment. Community participation in the tourism initiative is central to all the definitions, ranging from cooperative or individually owned and managed businesses to joint ventures between the community and the private sector. Other common themes are the involvement of external support from a donor agency or NGO, the generation of individual and collective benefits within the community and a triple bottom line approach.