Breast cancer remains one of the most common malignancies worldwide, with significant variations in incidence and mortality based on geographical, genetic, and lifestyle factors. This chapter provides a comprehensive overview of breast cancer, focusing on its epidemiology, diagnosis, pathology, staging, and treatment. It covers key diagnostic modalities, including imaging techniques, biopsies, and molecular testing. Pathological features of breast cancers are summarized, including histological subtypes and biomarkers that influence prognosis and therapeutic decisions. The staging of breast cancer, based on tumor size, nodal involvement, and metastasis (TNM), is discussed with tables, emphasizing its importance in guiding treatment strategies. Finally, the chapter reviews current treatment approaches, from surgery and radiation therapy to systemic treatments such as chemotherapy, hormone therapy, and immune therapy.