Herpes is a sexually transmitted infection (STI) caused by the herpes simplex virus (HSV) . There are two types of herpes simplex virus: HSV-1 and HSV-2. Both types can cause genital herpes, but HSV-2 is the most common cause of genital herpes. HSV-1 often causes oral herpes, which can result in cold sores or fever blisters on or around the mouth. However, most people with oral herpes do not have any symptoms.

In summary, herpes is an STI caused by the herpes simplex virus, and both HSV-1 and HSV-2 can cause genital herpes.