Stingrays are a group of rays, which are cartilaginous fish, related to sharks. There are eight families in total, but let’s keep it simple: sting rays are the small ones, bat rays are larger and then the manta rays are the really big ones.
There are sting rays and bat rays here in the California waters. My brother knows where to go look for them (in the San Elijo lagoon, using paddle boards) .. and indeed, we sighted some, scurrying on the sand below.