All links are inter-dependent. Lions may not eat grass, but if there is no grass, then what will the deer eat. With no grass, there will be no deer and hence no food for the lion. Similarly, the lion is also very important for the grass. If there is no lion, then the population of deer will go on increasing. Hence, the ever-increasing deer population will eat up all the grass, leading to decrease or complete loss of grass. So, by consuming the deer, the lion keeps the number of deer below a certain level. So there is no overgrazing of grass.

Food web: In any area, there are many food chains. Most plants and animals are a part of several chains. When you draw all the chains together, you will end up with a food web. Food webs are more informative than food chains because they show how consumers and producers are interconnected in nature.