There are several types of skin moles that can appear on human skin. They include:
Junctional moles
These moles are usually brown. They may be flat or slightly raised. The cells that make up the mole are usually located where the epidermis (top skin layer) and dermis (lower layer of skin) meet They are often dark are thin and only slightly elevated above the surface of the skin.
They are found all over the body and are regularly shaped — round or oval. They are uniform in color ranging from and light to dark brown. They can become cancerous, though are normally not a health issue.
Compound moles
This type of mole is slightly raised. It ranges in color from tan to dark brown. There are pigment-producing cells — called melanocytes — in both the epidermis and dermis (upper and lower layers of the skin).
Dermal moles
These moles range from flesh-colored to brown. They are elevated and are most common on the upper body. They can contain hairs
Sebaceous moles
This type of mole is produced by overactive oil glands in the skin. They appear yellow and have a rough texture.
Blue moles
Blue moles are are slightly raised and blue-black in color. They are colored by pigment deep in the skin. They can be most commonly found on the head, neck and arms of women.
Learn more about types of moles
There is more about various types of moles here: