Resource partitioning is the process whereby similar species exploit the limited resources in an ecological area without one species driving the others into extinction. Through natural selection, each species adopts a pattern of resource usage that isn't competitive.
Coexistence between direct competitors is impossible. If two species use the same resource in the same way, the stronger competitor will dominate and survive over the other. In resource partitioning, one species may feed during the day while another eats from the same source at night. One species may forage in the treetops while another forages on the ground. Similar species may evolve traits that allow each to exploit a distinct subset of the same resource.