Lung cancer comes in two main types: non-small cell and small cell. Each has different patterns, growth rates, and treatment needs. Smoking is the top risk factor, but 1 in 5 cases occur in people who have never smoked. Early detection is critical, yet most cases are found after the cancer has already spread. CT scans and biopsies guide diagnosis. Treatment now includes surgery, chemotherapy, immunotherapy, and targeted therapies. Multidisciplinary teams and lab-driven research are improving outcomes. Immunotherapy is especially promising by reactivating the immune system. Ongoing research is helping personalize care and extend survival for more patients.