True seals, also known as phocids, are a group of marine mammals that belong to the family Phocidae. They are characterized by their streamlined bodies, lack of external ear flaps, and the ability to move on land by wriggling on their bellies. True seals are found in various oceans and seas around the world, often in cold waters. These seals primarily feed on fish, squid, and crustaceans, using their sensitive whiskers to detect prey in the water. Unlike sea lions and walruses, true seals do not have the ability to rotate their hind flippers forward, which limits their mobility on land.