What is a convoluted spiral?

Spiral bound means you will have a spiral wire woven in a notebook or folder.

Spirals are curved lines that grow bigger and bigger from the center. I don't know how to relate your question specifically to arts and crafts without further information.

ear spiral, a thick spiral that is usually worn through the ear lobe

As the name suggests, the barred spiral galaxy has a barred central core. See related link for a pictorial

A spiral galaxy is a "spiral" without a physical bar structure. Whereas a barred spiral galaxy has an obvious central bar. See related pictorial for a better idea.