Wilhelm Konrad Röntgen was a German physicist who is best known for his discovery of X-rays in 1895. His groundbreaking work in the field of radiation earned him the first Nobel Prize in Physics in 1901. Röntgen's discovery revolutionized the fields of medicine, industry, and scientific research, and his name lives on in the unit of measurement for ionizing radiation, the "roentgen." Röntgen's work laid the foundation for the development of diagnostic radiology and medical imaging techniques that are still widely used today.