The adult pelage is stiff and lacks appreciable amounts of underfur. Eyebrow vibrissae are well developed, and mustache vibrissae are often beaded. A number of species have spotted color patterns, and some of the species of Phoca are the only pinnipeds with a banded pattern and with sexual differences in this pattern. The newborn are covered with a dense, soft, woolly, often white coat. There is an extensive amount of blubber.
Females generally have four mammae.
In males the testes are internal and the baculum is well developed. The upper incisors have a simple pointed crown, the canines are elongate, and the postcanines usually have three or more distinct cusps. Phocids shelter on rocky or sandy coasts, islands, and ice floes. Some stay on land or ice much of the time. Some migrate or disperse over a large area, and others make local movements corresponding to fluctuations of the ice.