Symbiosis
A mutually beneficial relationship between different groups.
Mutualism
The teaching that mutual dependence is necessary to social well-being.
Example : A bee and a flower
Commensalism
An association between 2 organisms in which one benefits and the other derives neither benefit nor harm.
Example : A whale and barnacles
Parasitism
It is a relationship between 2 things and one of them benefits from or lives off or each other.
Example : A flea(parasite) on a dog.