Moles are common skin growths with brown color caused by clusters of pigmented cells. They are usually harmless and appear in almost every human being. However, you should regularly go to your dermatologist and protect your skin from the sun rays.
On the picture above, you can see two moles. One of the moles is a time bomb which can explode at any time. The right reddish mole looks more like a pimple or a zit, but it does not go away.