audiovisual aids
type: Concept
narrower: optical storage devices

compact discs
type: Concept
broader: optical storage devices

computer storage devices
type: Concept
narrower: optical storage devices

concepts
type: Collection
type: ConceptGroup
member: optical storage devices

optical storage devices
type: Concept
broader: computer storage devices
broader: audiovisual aids
narrower: videodisc recording
narrower: compact discs

videodisc recording
type: Concept
broader: optical storage devices