If both organisms in a symbiotic relationship are executing an action, then one organism's actions benefit the other organism in the dynamic. The name for this type of symbiotic relationship is mutualism.
One example of mutualism is the relationship between sea anemones and hermit crabs. Sea anemones travel larger distances by attaching themselves to the backs of these crabs. While moving, the sea anemones extend their tentacles so they can consume the leftovers of a crab's food. The anemones return the favor by protecting the crabs from octopuses and other predators with their tentacles. The crabs also protect the anemone from starfish and worms. A similar symbiotic relationship exists between sea anemones and clownfish, where the anemone serves as the clownfish's shelter, while the clownfish protects the anemone from other predatory fish.
Another example of a mutual symbiotic relationship is found in goby fish and snapping shrimp. Because these shrimp have hindered vision, the fish protects the shrimp from predators when the shrimp are busy building a burrow. In exchange, the shrimp allows the fish to share its burrow.
The relationship between African oxpeckers and large African mammals is also a mutual relationship, although some observers also cite this as an example of parasitic symbiosis. The oxpeckers remove ticks from the backs of giraffes, hippopotamuses, zebras and elephants. These birds also alert the mammals to encroaching danger. In exchange, the mammals allow the oxpeckers to suck blood from any open wounds.