Rabbits and sheep both graze on shrubs, grasses, and other plants. the sharp rise in the population of rabbits in a region may result in a shortage of plants for sheep to graze upon. this relationship between sheep and rabbits is an example of

competition  

Explanation:

During competition there is an interaction between the species of plants and animals that compete for territory, food, or mating with the opposite sex and in which one of them is harmed.

One of these fights may be due to the consumption of some limited resource that both species need in order to survive, such as that of the shrubs in the example. This type of competition occurs all the time in all ecosystems.

When competition occurs between individuals of different species, it is called interspecific competition, and when it occurs between individuals of the same species it is called intraspecific competition.

It usually ends up surviving the most suitable species.