Nekton refers to the group of aquatic animals that can swim freely and actively in the water column, unlike plankton, which drift with currents. This category includes various species such as fish, squid, and marine mammals like dolphins and whales. Nekton plays a crucial role in marine ecosystems, often serving as both predators and prey. These organisms are typically found in oceans, seas, and some freshwater environments. Nekton is characterized by their ability to move against currents, allowing them to explore different habitats and find food. Their presence is vital for maintaining the balance of aquatic food webs.