Rays are remarkable members of the class Chondrichthyes, closely related to sharks, and are distinguished by their flattened bodies and expansive pectoral fins that are fused to the head. This unique body plan allows them to glide gracefully along the sea floor or through open water. They are primarily divided into families such as Dasyatidae (stingrays), Mobulidae (manta rays), and others, each with specialized adaptations.