X線, or X-rays, are a form of electromagnetic radiation that can penetrate various materials, including human tissue. They are commonly used in medical imaging to create pictures of the inside of the body, helping doctors diagnose conditions such as fractures, infections, and tumors. The discovery of X線 is attributed to physicist Wilhelm Conrad Röntgen in 1895. Since then, they have become an essential tool in both medicine and industry, allowing for non-invasive examination of objects and structures. Safety measures are important when using X-rays, as excessive exposure can pose health risks.