X-ray imaging is the oldest and most frequently used form of medical imaging for the entire body. It is a painless medical test that helps physicians diagnose and treat various conditions such as determining whether a bone has been fractured, locating foreign objects, and assisting in the detection and diagnosis of cancer.
X-rays are a form of electromagnetic radiation, just like visible light, and an x-ray machine is essentially a camera. Instead of visible light, however, it uses x-rays to expose the image.
To make an x-ray (radiograph), a part of the body is exposed to a small quantity of x-rays, and since bone, fat, muscle, tumors, and other masses all absorb x-rays at different levels; you see different shaded structures on the digital image that is produced.
When properly used by a radiologist and technologist specially trained to minimize exposure, x-rays are safe and no radiation remains afterward.