Unlike abiotic factors, which are physical factors like climate or soil structure, the biotic factors originate from the effects that living organisms have on each other in an ecosystem.
Organisms can have many different kinds of effects on each other. Some organisms compete with each other, some live in symbiosis and some feed on others like, for example. herbivores on plant and algae or carnivores on other animals.
So, biotic factors can be predation, cooperation, symbiosis etc.
