Warts are harmless skin growths caused by a viral infection in the top layer of the skin. The different types of warts are:

Common warts: They usually grow around the nails on the finger and on the back of the hands.
Flat warts: These are smaller and flat. They occur mainly on the face in children, or in the beard area in males and on the legs in females.
Plantar warts: These are warts which mainly grow on the soles of the feet and are known to grow inwards, occurring due to pressure of standing and walking. These are often painful.
Genital warts: Also known as condyloma, they occur in the genital areas of both males and females and are sexually transmitted.

Warts are contagious in nature and spread from person to person. The most contagious are genital warts whereas the other types have a poor index of contagion. The virus spreads easily if the skin is broken, which is why it is never a good idea to try and cut off the wart by yourself, for if partially done, it may only encourage the infection to spread more.