Here's a breakdown:

* Commensalism: A relationship where one organism benefits from the interaction, while the other organism is neither harmed nor helped.

Example:

* Barnacles on whales: Barnacles attach themselves to the skin of whales, gaining a stable environment and access to food as the whale swims. The whale is not significantly affected by the presence of the barnacles.

Other examples of commensalism:

* Birds nesting in trees: Birds benefit from the shelter and protection provided by trees, while the trees are unaffected.

* Remora fish and sharks: Remora fish attach themselves to sharks, using them for transportation and scavenging food scraps. The sharks are not significantly impacted.

Important Note: It can be difficult to definitively classify a relationship as commensalism, as there is always the potential for some subtle effect on the "unaffected" organism.