A biological ecosystem is a community of living organisms, such as plants, animals, and microorganisms, interacting with each other and their physical environment. These interactions include relationships like predation, competition, and symbiosis, which help maintain the balance of the ecosystem. Ecosystems can vary in size, from a small pond to a vast forest, and each supports a unique set of species. In an ecosystem, energy flows through food chains, where producers like plants convert sunlight into energy, and consumers, such as herbivores and carnivores, obtain energy by eating other organisms. Decomposers, like fungi and bacteria, play a crucial role by breaking down dead matter, returning nutrients to the soil and supporting new life.