An ecosystem is a complete community of interdependent organisms as well as the inorganic components of their environment; by contrast, a biological community is just the living members of an ecosystem. Within the study of biological communities there are a great number of complexities involved in analyzing the relationships between species as well as the characteristics of specific communities. Yet many of the concepts applicable to biological communities as a whole also apply to human communities in particular, and this makes these ideas easier to understand. For example, the competitive urge that motivates humans to war (and to less destructive forms of strife in the business or sports worlds) may be linked to the larger phenomenon of biological competition. Indeed, much of the driving force behind the development of human societies, as it turns out, has been biological in nature.