An ecosystem is composed of:

1.       an area's non-living component, or its physical nature and meteorological climate-related parameters;

2.       an area's living component, or all its living creatures

3.       the combination of all the relationships between each member of the components above, or the so-called ecological relationships below:

·         habitat relationship, the relationship between organism-environment

·         the food chain, the relationship between organisms in terms of who-eats-whom.

Animals procure the nutrition they need by eating plants or other  animals that have eaten plants themselves.

Whenever a herbivore eats a plant and then the herbivore is eaten by a carnivore, the sequence of events is known as the food chain or trophic sequence.