Final answer:
White spots on the nail caused by injury and separation from the nail bed are known as trauma to the nail or subungual leukonychia, with the nail bed located beneath the nail plate. These spots move up and are eventually trimmed off as the nail grows.
Step-by-step explanation:
White spots on the nail caused by an injury where there is a separation between the nail and the nail bed is known as trauma to the nail or subungual leukonychia. This condition is not harmful and usually a temporary issue. The nail bed is under the hard nail plate and looks pink because of the blood vessels present. When the nail gets injured, these spots can appear as a result of the temporary disruption of nail growth from the matrix beneath the cuticle. Over time, as the nail grows out, these spots usually move upwards and will be trimmed away as you cut your nails.