Competition for resources occurs when there is some resource that is needed by more than one species. The two (or more) species have to compete to get that resource. For example, imagine that there are wolves and mountain lions in a given area and they both eat deer. The two carnivorous species would have to compete for the deer. This will not always be a problem, but there will be times when there are not enough deer to go around and one or both species of carnivore will suffer.
Human beings and animals compete for many resources. Of course, since humans are much more powerful than other animals, the competition is rather one-sided. One major resource for which they compete is habitat. Human beings want land for farms and homes. When they take the land, many animals can no longer live in that habitat. Human beings also compete with some animals for food. For example, humans fish the oceans, taking many fish for their own consumption. When they do so, they take fish that larger fish would otherwise have eaten. These are both instances of humans and animals competing for resources.