Herpes Simplex Virus (HSV) is a prevalent and contagious viral infection caused by two types of viruses: HSV-1 and HSV-2. These viruses are responsible for oral and genital herpes infections. HSV-1 typically causes oral herpes, leading to cold sores or fever blisters around the mouth and face, while HSV-2 primarily causes genital herpes, resulting in sores or blisters in the genital and anal areas.