Herpes is a family of viruses that infect humans and cause a range of diseases depending on the type of herpes virus and the host's reaction to the virus.
Herpes virus 1, herpes simplex 1, is responsible for cold sores (fever blisters). It is called oro-facial herpes because of its tendency to infect the lips and face.
Herpes virus 2, herpes simplex 2, is genital herpes. It has a strong tendency to infect the genitals and is a sexually trasmitted disease. It can also infect other areas of the body and can spread inside the body, causing viral meningitis among other symptoms.
Herpes virus 3, varicella zoster, is responsible for causing chickenpox and shingles.
Herpes virus 4, Epstein-Barr virus, is responsible for causing mononucleosis among many other diseases.