THERE ARE SEVERAL types of swivels, but they work in much the same way with eyes that twist independently to prevent line twist.
Rolling swivels are round, usually with round eyes, diamond swivels have a diamond-shaped eye rather than round, while barrel swivels are the type usually made from brass with a twist of wire at each eye.
Another is called the crane swivel because its body resembles the assembly on a crane’s hook.
