Some examples of symbiotic relationships in nature include:
Mutualism: where both species benefit from the relationship, such as bees and flowers. Bees benefit from the nectar and pollen of flowers, while flowers benefit from the pollination done by bees.
Commensalism: where one species benefits and the other is neither helped nor harmed. An example is the relationship between barnacles and whales. Barnacles attach themselves to whales, gaining a place to live and feed, while the whales are not significantly affected.
Parasitism: where one species benefits at the expense of the other. A common example is the relationship between ticks and mammals. Ticks feed on the blood of mammals, harming the host in the process.