This chapter provides a comprehensive overview of cancer, with a focus on oral cancer. It begins by discussing the historical understanding of cancer, its multifactorial origins, and major risk factors such as tobacco use, alcohol consumption, obesity, infectious agents, radiation exposure, and genetic predisposition. The anatomy of the oral cavity is detailed to highlight the structures susceptible to oral cancer, including the lips, gums, tongue, and palate. Oral cancer, primarily oral squamous cell carcinoma (OSCC), is identified as a significant global health issue, with high incidence and mortality rates, particularly in India. The chapter explores the risk factors for oral cancer, including tobacco, alcohol, and human papillomavirus (HPV), and emphasizes the importance of prevention strategies such as tobacco cessation, alcohol moderation, HPV vaccination, and early detection. It concludes by underscoring the need for public health initiatives and regular screenings to reduce the burden of oral cancer globally.