Which of the following best describes "residual data"?

Residual data refers to pieces of information that remain on a storage medium even after they have been deleted. This is significant in digital forensics because deleted files do not vanish completely; instead, their data sectors are often untouched until they are overwritten by new information. Even when a user thinks they have permanently erased a file, traces of it can linger, making it potentially recoverable through various forensic techniques.

In the context of this question, the other options do not accurately reflect the nature of residual data. Data currently in use is actively engaged and not deleted, long-term stored data implies that it is deliberately kept and also is not in the deleted state, and temporary data files are active but transient in nature, typically intended for short-term use. Therefore, the definition pertaining to data that has been deleted but can still be recovered captures the essence of residual data effectively.