Let's limit "nature" to the biosphere itself. The biosphere is not the entire planet Earth. The biosphere is only the sections of the planet where life can successfully exist. In miles, the biosphere extends about 5 miles up into the atmosphere and 5 miles below sea level. Within that biosphere, nature is divided into different biomes/ecosystems. Those ecosystems include everything that is living and non-living within it that affects the environment. Living (biotic) factors will be any and all of the the plants, animals, fungi, bacteria, and protists that live in the area. The non-living (abiotic) factors will be things like average temperatures, wind, rainfall, air quality, amount of sunlight, etc. An entire ecosystem is generally what a person is talking about when referring to the physical "being" of nature.