A confusing aspects to this has to do with there being several forms & blends of iodine. But once we see the commonly used forms laid out together, I think the situation becomes pretty simple. If these (KI) and (I2) labels are confusing or overwhelming, just skip past them for now or try to remember them by the sound they make etc. We don’t need to know these details, but being aware of the different forms and names makes learning other aspects to iodine much easier.
There are two main “raw” forms of iodine used for health. Potassium Iodide(KI) and elemental iodine(I2). Any of the forms we want to use for healing are going to contain either or both of these along with distilled water. There are forms of iodine with alcohol instead of water that we don’t want to use for this purpose.