What is the clinical difference b/t a mole and a lentigo? Are lentigo smaller than moles? Lighter? Are moles elevated more often? How do you tell?

A big answer. A tough one to answer in such a short space. A mole is a benign growth of pigment producing cells (melanocytes). A lentigo (aka liver spot) is similar but more due to an increased amount of pigment in the bottom layer of the epidermis. Moles are often elevated but don't have to be so. Lentigos are usually flat but can also be raised. Seeing a dermatologist can help you sort this out. Helpful?
Cells vs. Pigment. A mole is a collection of cells called melanocytes. Melanocytes produce skin pigment, giving people their normal skin color. When melanocytes grow in a cluster, they form a mole, which can be flat or raised. A lentigo is a slight increase in the number of melanocytes in an area of the skin. These cells increase pigment in that area, causing a lentigo (freckle).