A killer whale is both a dolphin and a whale. Killer whales are orcas of the genus Orca in the family Cetacea. All animals under the orcas can be called whales, so orcas are undoubtedly whales and belong to toothed whales among whales. And killer whales are dolphins, so they can also be called dolphins. People usually think that dolphins and whales are different. The big ones are whales and the small ones are dolphins, but in fact they are both whales.

1. Bottlenose dolphins: These dolphins are common in aquariums, and their color is gray and black. They have high IQ and are often trained to complete various complicated performances. In addition, they are also distributed in the ocean, and they may be seen in the Pacific Ocean and the Atlantic Ocean.

2. Chinese White Dolphin: This dolphin is common in the East China Sea and also distributed in the Indian Ocean. This is a pink dolphin, and its color is rare.

3, Pilot Whale: This is a very large dolphin, and the length of a relatively large individual can reach 20 feet. The background color of some individuals is black, while others are white. They often appear in groups and generally live in warmer waters, so they are more common in low latitudes.

4. Port Dolphins: Unlike the other dolphins, this is a relatively small dolphin species. They are shorter and fatter, only about 5 feet long. Their body color is brown.