Images of internal organs, bones, and tissues can be captured on film or in digital form using X-rays, which emit invisible electromagnetic energy beams. Standard X-rays are used for a variety of purposes, such as the diagnosis of malignancies and bone injuries. To create pictures of the body, its organs, and other internal structures for diagnostic reasons, X-rays use external radiation. A "negative" type image is created when X-rays penetrate human structures and land on specially prepared plates (similar to camera film) or digital media (the more solid a structure is, the whiter it appears on the film).