An ecosystem is a functional unit of nature where living organisms interact with each other and with the physical environment. It includes both biotic (living) and abiotic (non-living) components.
Energy flows through the ecosystem in a unidirectional manner from the sun to producers and then to consumers. Energy decreases at each trophic level according to the law of thermodynamics.
A food chain represents the linear transfer of energy from one organism to another, whereas a food web shows interconnected food chains within an ecosystem.
Ecological succession is the gradual change in species composition of a community over time. It may be primary or secondary succession.
Ecosystems provide essential services such as oxygen production, climate regulation, soil fertility, and water purification, which are crucial for human survival.