X-rays are images created using electromagnetic waves. X-ray imaging creates black and white pictures of the inside of your body. Because different tissues absorb different amounts of radiation, some areas appear to be dark and others light. Air absorbs very little radiation so it appears black, calcium in bones absorbs x-rays the most, so bones look white, and fat and other soft tissues absorb some radiation so they look gray.
When we think of x-rays, most of us think of broken bones, but x-rays are also used in other ways. For example, chest x-rays can spot pneumonia and mammograms use x-rays to look for breast cancer.
The amount of radiation you get from an x-ray is small. A basic x-ray gives out a radiation dose similar to the amount of radiation you're naturally exposed to from the environment over the course of a week or two.