What is the difference between a freckle and a mole ?

A freckle is a collection of the skin pigment melanin in the skin, but in a concentration. Some people who are very freckly, have very pale skin in-between their freckles, so they have little patches of skin which makes the pigment not many cells which make the pigment outside that patch. A mole is the cells in the skin which make the pigment but more them in a lumpy patch.