There is no difference between malignant lung nodules and lung cancer. Lung nodules are lung lesions with lesions smaller than 3cm, which are clinically categorized into benign lung nodules and malignant lung nodules, and malignant lung nodules are also known as lung cancer. Lung cancer is defined as malignant tumors of the lungs of all sizes and is the malignant tumor with the higher incidence. Malignant lung nodules found on imaging often have small lesions, and therefore should be adequately evaluated and treated with aggressive surgery, with most having a better prognosis. Lung cancers with larger lesions, or those with metastases, often have a poorer prognosis, so people with risk factors should be screened for lung cancer for early detection and treatment.