Your nature is sort of the way you are — the sum total of how you think, feel, and behave. It might be in your nature to remain calm and level-headed when faced with a difficult challenge.
Things that aren't people can also have their own nature. You might notice the frantic nature of a political debate, or you might question the nature of your brother's friendships. Nature can also refer to the physical world made up of plants and animals: what you think of as "the great outdoors." You might be a nature lover who enjoys hiking. Nature can also describe natural forces, such as the destructive elements of nature, like a tsunami or a tornado.