Epstein-Barr Virus (EBV) is a member of the herpesvirus family, primarily transmitted through saliva. Its biological activity includes infecting B lymphocytes and epithelial cells, leading to cell proliferation and latent infection. EBV infection can cause infectious mononucleosis, clinically presenting with symptoms such as fever, sore throat, swollen lymph nodes, and fatigue. Additionally, EBV is associated with certain cancers like Burkitt's lymphoma and nasopharyngeal carcinoma.