Naitur, in the broadest sense, is the naitural, pheesical, or material warld or universe. ""Naitur"" can refer tae the phenomena o the pheesical warld, an an aa tae life in general. The study o naitur is a lairge pairt o science. Awtho humans are pairt o naitur, human activity is eften unnerstuid as a separate category frae ither naitural phenomena.