Ecology is the scientific study of interactions between organisms and their environments, focusing on energy transfer. It examines these relationships across multiple levels of organization, from organisms to populations to communities and ecosystems within the biosphere. A key concept is the niche, which describes an organism's role within a community based on how it obtains resources and avoids limiting factors like competition. Energy and matter are transferred between trophic levels through various feeding relationships between producers, consumers, and decomposers that make up food chains and webs within an ecosystem.