Explanation
CDfs is a virtual file system for Unix-like operating systems; it provides access to data and audio tracks on Compact Discs. When the CDfs driver mounts a Compact Disc, it represents each track as a file. This is consistent with the Unix convention "everything is a file". Source: https://en.wikipedia.org/wiki/CDfs

Explanation
According to the Executive Office of the President, Office of Management and Budget (OMB), and the U.S.
Department of Commerce, Office of the Chief Information Officer, PII refers to "information which can be used to distinguish or trace an individual's identity." The following are a few examples:
- An individual's name
- Social security number
- Biological or personal characteristics, such as an image of distinguishing features, fingerprints, Xrays, voice signature, retina scan, and the geometry of the face
- Date and place of birth
- Mother's maiden name
- Credit card numbers
- Bank account numbers
- Driver license number
- Address information, such as email addresses or street addresses, and telephone numbers for businesses or personal use
- Cisco CyberOps Associate CBROPS 200-201 Official Cert Guide Omar Santos