Human papillomaviruses (HPV) are common viruses that can cause warts. There are more than 100 types of HPV. Most are harmless, but about 30 types put you at risk for cancer. These types affect the genitals and you get them through sexual contact with an infected partner. Vaccines can protect against several types of HPV, including some that can cause cancer.
Click here for more information http://www.nlm.nih.gov/medlineplus/hpv.html