How ROM Works

ROM Types

There are five basic ROM types:

  • ROM
  • PROM
  • Flash memory

Each type has unique characteristics, which you'll learn about in this article, but they are all types of memory with two things in common:

  • Data stored in these chips is nonvolatile -- it is not lost when power is removed.
  • Data stored in these chips is either unchangeable or requires a special operation to change (unlike RAM, which can be changed as easily as it is read).

This means that removing the power source from the chip will not cause it to lose any data.