A snapshot is a photograph taken without preparation. It is shot spontaneously and quickly, most often without artistic or journalistic intent (see Wikipedia).
While I mostly agree with the first part of this definition, I am not sure what "artistic intent" really means. If there is no artistic intent, is the picture less artistic? Does artistic intent necessarily entail previous planning and preparation? And if it does, are spontaneous shots inartistic? Do you need to be a professional to capture a beautiful picture? I certainly do not believe so. For me, the best pictures are not necessarily planned, quite the contrary, they capture fleeting and animated moments of a particular time and space. They are impressions or views of something brief or transitory. And that something can be the inexhaustible life and beauty that surrounds us.
This is the amateur work of a nature enthusiast who happens to encounter such moments by chance. Whether a grimace or a sudden gesture, a flying bird and its spreaded wings, a play of light through the boughs and the forest, the splashing colors of autumn and trees, the orange sky of the sunset or the green bed of grass and the fallen leaves. There are just tiny details scattered all around us, waiting to be seen.
Nature can refer to the physical world, and also to life in general.
Because in our technological world, it is so easy to forget about all the life that surrounds us.
