Optical media is storage that is read with light, such as CDs, DVDs, and Blu-ray discs, rather than by purely electrical memory cells. Data is encoded as pits, lands, or similar patterns on a reflective surface, and a drive uses a laser to read it. Because the medium and reader are separate physical systems, optical media has different error modes, latency, and trust assumptions than flash storage or RAM.
In cyber security, optical media matters because any new storage path changes the attack surface. A system that accepts discs must parse file systems, handle malformed sectors, and tolerate read errors without crashing or misinterpreting content. Defenders may use optical media for controlled offline distribution, preservation, or software installation, while attackers can abuse unexpected disc contents to trigger parser bugs or supply tampered data. The core lesson is that every medium brings its own validation and integrity checks.