Moles are common benign growths of the cell that makes pigment in the skin, the melanocyte. Most people have moles, and some have more then others. Moles can be flat or raised. They can vary in color from pink, to tan, brown, and sometimes black. The vast majority of moles are benign, but sometimes moles are abnormal and rarely they can be cancerous (melanoma). Moles can change slowly over time, but when a mole is changing quickly this can be cause for concern. It's important to have a baseline skin exam, even if you think your moles are normal. Any changing mole should be evaluated by a dermatologist.
There are many different types of other growths that occur on the skin. As you age, seborrheic keratoses are more likely to appear. These are often brown or tan, raised, warty/rough growths. Seborrheic keratoses are benign, but they can become bothersome if they are itchy or irritated by clothing. In these cases, a dermatologist can treat the growth with cryotherapy (freezing) or other techniques.
Examples of other types of growths that can be treated by a dermatologist include skin tags, cysts, warts, and lipomas.