The difference between them is that they have different habitats, different characteristics, different shapes for example 

Dolphins and porpoises belong to the same order of whales, but usually dolphins are called toothed whales while whales are called baleen whales. • The body size of whales is much larger than that of dolphins. • Dolphins have teeth but not whales. In contrast, whales have a filter structure in their upper jaw but not dolphins. • Dolphins are said to be smarter than whales.

Antelope species belong to the group of toothed whales while blue whales, fin whales and humpback whales belong to another category. Blue whales, which are the largest of all whale species, range in length from 80 to 100 feet while dolphins range in length from 6 to 12 feet. The main difference that can be seen is that dolphins have teeth while baleen whales have no teeth. Dolphins are fast swimmers. Whales have a slow speed because they have large bodies. Whales mainly grow on plankton, krill, small marine life and small crustaceans. Dolphins are known to thrive on fish and large marine animals. Whales tend to move alone unless they migrate or mate. In contrast, dolphins swim in groups. Dolphins like to live together.

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