Definition
A small optical storage disc used to hold digital data, audio, or video. In aviation training contexts, CDs have historically been used to distribute training materials, simulations, and reference content that supplement printed handbooks.
Plain English
A round, shiny plastic disc that stores information you can play or read on a computer or CD player. Instructors have used CDs to share training videos, practice tests, and study material with students.
Context Anchor
Seen in older aviation training materials, instructor resources, and course media references.
Derivation
Compact' comes from the Latin 'compactus' meaning 'closely packed,' and 'disk' comes from the Greek 'diskos' meaning a flat round object. The name reflects that a lot of information is packed onto a small flat disc.
Why Pilots Care
Pilots and instructors may still encounter older training resources distributed on CD, especially legacy ground school materials, and need to recognize the format when referenced in instructional guidance.
Intuition Check
Do not read CD here as another aviation abbreviation, such as a clearance-related term. In this glossary entry, CD means Compact Disk, a physical storage disk for digital information.
Example Sentence 1
The instructor handed out a CD containing supplemental videos to review before the next ground school session.
Example Sentence 2
Before the lesson the student loaded the training CD into the computer to review aircraft systems.