Biologists and other scientists use a variety of concepts to capture the surrounding conditions of their chosen units of analysis. In this chapter we examine two sorts of concepts: environment and niche concepts. We discuss how such concepts developed, how they are understood, and how they are used in the life sciences and beyond. By identifying their similarities and differences, we arrive at a sense for both the common features of concepts used to characterise the surroundings of organisms an other entities, as well as the variety of ways in which these concepts can be adapted to fit a variety of purposes and contexts in scientific research. ( direct link )