X-ray may refer to any of the following:
1. First discovered by Wilhelm Röntgen on November 8, 1895, an x-ray is a short energy beams with wavelength in ranges of 0.01 to 10 nanometers. X-rays are used to display the contents of an object, such as the contents of a package, luggage, or the human body. The picture shows an example of what a computer laptop looks like in an X-ray picture.
The first X-ray photograph was done by Nikola Tesla.