Read-mostly memory
Read-mostly memory (RMM) is a type of memory that can be read fast, but written to only slowly. Historically, the term was used to refer to different types of memory over time: In 1970, it was used by Intel and Energy Conversion Devices to refer to a new type of amorphous and crystalline nonvolatile and reprogrammable semiconductor memory (phase-change memory aka PCM/PRAM).