Can You Explain What Is Meant By An "Ecosystem"?

An ecosystem is an ecological system formed by the interaction of living organisms and their non-living environment. Thus when considering an ecosystem we are considering both the physical and the biological factors operating in such a system.

In any ecosystem the living organisms can be identified as producers, consumers or decomposers. Producers are the green plants that can manufacture complex organic food substance from raw materials. They are the only organisms that can convert radiant energy into chemical energy and store it in their food molecules during the process which is called photosynthesis. Producers affect the lives of other organisms because they are the beginning of a food the chain. They provide food substances, energy and oxygen for other organisms in the food chain accordingly.

Consumers obtain their energy from other organisms upon which they feed. Animals are therefore consumers. Herbivores (e.g. cows, goats, zebras etc) feed directly on plants. Hence they are known as primary consumers, and carnivores (e.g. lions, cheetahs etc) which feed on herbivores are known as secondary consumers.
Decomposers (e.g. fungi and bacteria) act on dead organism and enable the materials locked up in them to be returned to the environment and be used again by the green plants.

Hey can you explain what is eco-system?

It is the sum total of all life in a given area plus life's interaction with the non-living portions of the area. An econiche is the limited ecosystem of a particular group of organisms. An ecosystem consists of a number of overlapping and interacting econiches and, in fact, is the largest functional unit in ecology because it includes both living (biotic) and non-living (abiotic) environments.

Abiotic components of an ecosystem include all non-living material viz. air, water, soil, minerals, and biogenic salts.
Biotic components can be divided into several categories:

(I) Producers: These comprise photosynthetic plants utilising solar energy directly, along with various salts and water. They dominate terrestrial (land) ecosystems as they are the most abundant of all groups.
(II) Consumers: They are divided into primary and secondary consumers; the former, utilising producers directly, and are herbivorous in nature, and the later, consuming primary consumers, are secondary consumers or carnivorous. These are tertiary consumers as well which are obviously carnivorous.
(III) Decomposers: Fungi and bacteria comprise this group which obtain energy mostly from the dead tissues of consumers. They release simple substances to the environment as by-products of their metabolism. The producers can use these products and thus the indefinite cycle goes on.

Plants capture the sun's energy and use it to convert inorganic compounds into energy providing organic compounds. So nutrients in the soil are changed to leaves, fruit, tubers etc. This process is known as photosynthesis.
This becomes the first step in a chain whereby animals eat plants and in turn are eaten by other animals. The energy is converted and passed on each time and is passed on up the food chain.
Finally it ends with the animal dying. The corpse is then broken down and used as food or nutrition by bacteria and fungi. As these organisms, which are called decomposers, live off the dead animals, they break down the complex organic compounds into simple nutrients again. These decomposers play an vital part because they take care of breaking down and therefore cleaning up all the dead matter which would otherwise be littering the planet. The simple compounds again return to the soil to feed the plants.
There are reckoned to be over 100,000 different decomposers at work right now.

The term ecosystem refers to the combined physical and biological components of an environment.

Ecosystem is the natural unit which consists of all plants, animals and the microorganisms in a specific region who function together with all of the abiotic factors. Abiotic factors are the non-living physical factors of the environment. The term ecosystem was introduced by Roy Clampham in 1930 and then the British ecologist Arthur Tansley refined the term and described it as a whole system including complex organisms and the physical factors of the environment.