Acronym for Read Only Memory. ROM is a type of memory chip where the data is programmed (sometimes called masked) into the chip as it is manufactured. Unlike RAM and other technologies it cannot later be changed, reprogrammed or rewritten (which is where the Read Only name comes from). The data stored in a ROM is often referred to as “firmware” since it cannot be changed unless the physical chip is swapped with one having different programming. ROM chips are used in all kinds of electronic computing devices. They often carry the instructions that define the basic operating properties or fixed sets of data required by the device that don’t often change. If it is believed that the data in a ROM chip will need to be changed from time to time the reprogrammable EPROM has often been used, though today there are many other viable solutions.