All rays belong to the superorder Batoidea, which includes stingrays, electric rays, skates, guitarfish, and sawfish. Like sharks—their close relatives—batoids have skeletons made of tough connective tissue called cartilage. About 480 species of batoids are distributed worldwide, particularly in warm and temperate climates, and are found in oceans, estuaries, freshwater streams, lagoons, lakes, shallow offshore waters, and coastlines.

Rays primarily feed on molluscs, crustaceans, worms, and occasionally smaller fishes. Some rays crush their prey between their blunt teeth, sometimes referred to as bony plates. Often completely burying themselves in the sand or soft sediment, rays are camouflaged by a grayish-brown, often mottled coloration.

Reminiscent of birds in flight, some rays gently flap their enlarged pectoral fins, or "wings," to "fly" through and sometimes even leap out of the water. A ray’s wingspan, or disc-size, can range from about 30 cm (12 in.) in yellow stingrays to over 6.1 m (20 ft.) in manta rays.

Among the best know rays are stingrays, which have long, slim, whiplike tails armed with serrated, venomous spines. A stingray lashes its tail only as a defensive measure when it is caught, stepped on, or otherwise disturbed.

When wading in shallow waters, people should shuffle their feet to avoid stepping on a buried stingray.

In many parts of the world, some rays are commercially important food sources, yet currently, rays are not considered threatened or endangered. Due to humankind’s impact on the marine environment, however, concern is mounting for the future of rays throughout their range.