Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general. It ranges in scale from the subatomic to the cosmic.
Science wants to understand nature. Therefore it is important, how the word nature is defined:
Nature is everything that was not made by man. So the definition of nature excludes all things that where introduced by mankind. All those human developments are summarized as culture.
The definition of nature summarizes natural objects, e.g.
• stones
• animals
• plants
It also reflects on events in nature like
• the wind
• the rain
• earthquakes etc.
Nature can be divided in a living and a not living (abiotic) part.
Living nature
Living nature in a forest
The living part of nature consist of all life on earth.
• plants
• animals
• mushrooms
• bacteria
Only the following categories existed in earlier definitions of nature:
1. the animal kingdom, and
2. the plant kigdom
Today, additional categories have been added:
1. Bacteria, die nur aus einer Zelle bestehen, deren Erbgut aber im Gegensatz zu den anderen Lebewesen nicht im Zellkern zu finden ist, sondern in der ganzen Zelle verteilt ist.
2. Die Einzeller, die bereits einen Zellkern besitzen, die aber noch nicht eindeutig dem Pflanzen- oder Tierreich zuzuordnen sind.
3. Die Pilze als abbauende Lebewesen, die man früher den Pflanzen zugeordnet hat, denen aber das Blattgrün fehlt und die man deswegen einer eigenen Gruppe zuordnet.
Another category was recently added:
• Die Archaeen
o A group of the oldest beings, for example, the methane lifeforms, which thrive in extreme conditions.
Of course man himself is part of the living nature, because he still counts as an animal.