Read Only Memory

computer memory that can be easily accessed but does not allow alteration of its data

The notion of read-only data can also refer to file system permissions. Read-only memory (usually known by its acronym, ROM) is a class of storage media used in computers and other electronic devices. Because data stored in ROM cannot be modified (at least not very quickly or easily), it is mainly used to distribute firmware (software that is very closely tied to specific hardware, and unlikely to require frequent updates).
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Noun
1. (computer science) memory whose contents can be accessed and read but cannot be changed
(synonym) ROM, read-only storage, fixed storage
(hypernym) memory, computer memory, storage, computer storage, store, memory board
(hyponym) CD-ROM, compact disc read-only memory
(classification) computer science, computing

read only memory, ROM, nonvolatile memory containing permanently inscribed data that cannot be supplemented changed or deleted (Computers)

A memory in which data, under normal conditions, can only be read. Synonym nonerasable storage.