Short for Erasable Programmable Read-Only Memory, EPROM is a non-volatile memory chip that was invented by Dov Frohman in 1971 while at Intel that can only be read. If exposed to ultraviolet light an EPROM can be reprogrammed if needed, but otherwise does not accept or save any new data. Hardware manufactures use EPROM when it may be needed that the data contained on the EPROM needs to be changed. An EPROM chip is distinguishable by a small quartz crystal (not glass) circle window that exposes the chip so that can be reprogrammed. In the picture shown on this page is an example of an Intel 8048 made by NEC and is an example of an EPROM chip.
Today, EPROM chips are not used in computers and have been replaced by EEPROM chips.