The name "pinniped" derives from the Latin words pinna "fin" and pes, pedis "foot". The common name "seal" originates from the Old English word seolh, which is in turn derived from the Proto-Germanic *selkhaz.

Pinnipeds have streamlined, spindle-shaped bodies with reduced or non-existent external ear flaps, rounded heads, flexible necks, limbs modified into flippers, and small tails. Pinniped skulls have large eye orbits, short snouts and a constricted interorbital region.

Pinnipeds have an amphibious lifestyle; they spend most of their lives in the water, but haul out to mate, raise young, molt, rest,

• "Seal Conservation home page". Seal Conservation Society.
• "Pinnipeds: Seals, sea lions, and walruses". Department of Fisheries. National Oceanographic and Atmospheric Administration. Archived from the original on 19 July 2014.

Taxonomy
The German naturalist Johann Karl Wilhelm Illiger was the first to recognize the pinnipeds as a distinct

Living pinnipeds mainly inhabit polar and subpolar regions, particularly the North Atlantic, the North Pacific and the Southern Ocean.

Cultural depictions
Various human cultures have for millennia depicted pinnipeds. The anthropologist, A. Asbjørn Jøn, has analysed beliefs of the Celts of Orkney and Hebrides who believed in selkies—seals that could change into humans and walk on land.