We said that you use a synchrotron light source to generate photons. Photons are light, so that’s why it’s called a light source. Often the photons you want are X-rays, which are photons with a short wavelength: 0.01 nanometers to 10 nanometers. The light we can see with our eyes has wavelengths of hundreds of nanometers.
Electrons traveling at close to the speed of light lose energy and give off the X-ray photons, which are drawn off in tangents while the electrons continue in a circle. You then make those X-rays hit a sample that you are doing some science on.
X-rays are often used by doctors to take photographs through the skin. So that’s one use of them. Can you think of another reason people would want to use extremely bright X-rays to study samples of material using a synchrotron?