why do the animals,the vegetation and the way people live vary from place to place ?

Vegetation, animals and people vary from place to place due to variations in environment. People adjust to different climatic conditions and adapt their lifestyle to suit the environment. At the same time, they also make efforts to keep modifying the environment. Natural pre-conditions determine the presence of  different forms of vegetation and animals. Human intervention also causes variation as humans cultivate crops and domesticate animals which are suited to the environment of the place.