A symbiotic relationship occurs when two organisms, individuals or groups of people work together by helping one another with the intent of getting help in return. In a symbiotic relationship, the two people or groups of people live together to provide the greatest benefits to one another.
Symbiotic relationships can be either obligate or facultative. In an obligate relationship, the two organisms cannot live or function without one another. While in a facultative relationship, the organisms are not dependent on one another but live together by choice. The four main types of symbiotic relationships include mutualism, commensalism, parasitism and competition.