On this page, there are pictures of baleen whales, which are mysticeti ('proper' whales), but also photos of sperm whales and beaked whales, which are odontoceti like dolphins and porpoises.

Odontoceti use echolocation, have teeth (more information here), one blowhole, a melon, a dorsal fin near the middle of the body, a strong social structure, and the male is often larger than the female.

Mysticeti don't use echolocation, have a baleen, two blowholes, no melon, a dorsal fin nearer to the back of the body, little social structure, and the female is larger than the male.