What's the difference between iodine and betadine?

Topical Betadine. Betadine is the brand name for several topical preparations (scrub, spray, swabs, pads, etc) with 5-10% povidone-iodine, a strong antiseptic, used to prevent bacterial growth. Iodine is a chemical element that the thyroid gland uses to synthesize thyroid hormone. If you mean tincture of iodine, this is a disinfectant, with 2-7% iodine. Betadine is less toxic to human cells than tincture of iodine.
Betadine is an iodin. Betadine uses iodine as a component of it formulation. It is an antiseptic.