A "cetacean" is a type of marine mammal that includes whales, dolphins, and porpoises. Cetaceans are characterized by their adaptations to life in the water, such as streamlined bodies, the presence of a blowhole for breathing, and the ability to communicate through a variety of vocalizations. They are highly intelligent animals with complex social structures and behaviors. Some species are known for their playful nature and strong social bonds. Cetaceans are crucial to marine ecosystems, influencing food webs and biodiversity. Many species face threats from human activities, making conservation efforts important for their survival and the health of ocean environments.