Types of Symbiotic Relationships

Symbiotic relationships exist in every ecosystem. Symbiosis is a long-term interaction between different species that interact in close proximity. There are three types of symbiotic relationships: mutualism, commensalism, and parasitism. Mutualism is a relationship that benefits both species involved. Commensalism is a relationship in which one species benefits from the interaction, but the other is not affected. Parasitism is a relationship in which both species involved are harmed. The next few pages will provide you with examples of each type of symbiotic relationship.


Source
http://www.teachersdomain.org/resource/nat08.living.eco.humeco.lpsymstra/