In the literature on different forms of online collaboration, a growing variety of empirical phenomena is subsumed under labels such as “crowdsourcing” or “community”. Defining online collaboration as a form of organizing self-selected actors leading to a joint outcome, we try to clarify these concepts in form of a three-dimensional continuum. On one end, the crowd model is characterized by low task interdependence, central control and automatization as well as by a low level of interaction among its members. On the other end, the community model allows for high task interdependence, decentralized control and a high level of interaction among its members. We then locate ten cases discussed in the literature within this continuum and assess the implications of conceptually differentiating between crowds and communities for open innovation processes. We conclude that the innovation potential of the community model is greater than that of the crowd model, while being associated with a greater loss of control.