How do i find what's the difference between a mole, skin tag, and cancer?

A biopsy: A skin tag tends to look like a grainof rice or small tag coming from the skin they are no cancerous more common in overweight persons with redundant folds of skin the neck and axilla are common places. A mole is a growth of cells on the skin normally bening but some can change and that is why you should see a dermatologist. Moles tend to be round smoothed walled and ma have hairs.