Ecosystems are so varied in form and structure that whatever has a distinct community of its own, can be called an ecosystem eg. A crop field, grass land, barks etc. all the ecosystems are divided into the two categories.

1.      Natural-ecosystem:

These ecosystems operate by themselves under natural conditions without any major external interference. For example Grassland, Forest. It is of two types:

(i)    Terrestrial Ecosystem: this ecosystem is land operated. If main vegetation is grass then it will be known as grassland ecosystem and if it is dense forests then it is called as forest ecosystem.

(ii)   Aquatic Ecosystem: operational area of this ecosystem is water eg. Pond.

2.      Artificial Ecosystem:

These ecosystems are made and maintained artificially by lman eg. Maize, wheat, rice fields etc.